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Accessing the Dropbox site disables my internet connection

I have never seen anything like this. I visit http://www.dropbox.com

I don’t even have to log in. I just browse around then shortly thereafter my whole internet connection is down but working perfectly fine on all other devices! The issue is definitely drop box as it is completely repeatable every time I visit drop box. It also happens when I download the Dropbox app from the App Store. The issue does not happen if I don’t visit drop box.

it’s so frustrating that a virus maker could learn a thing or two from Dropbox on how to make malware. I need help to resolve this.

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Neal

Hi everyone!

Thanks for reporting this to the Community.

I have actually been collecting all of the reports of this across the community and and Reddit as well, to put together a cohesive report for our internal team. This is now being looked into and hopefully we will have a fix soon.

In the meantime, here is the results of some of our investigations and steps you can take:

Avast

At this time, we are not certain of the feature causing the problem. We suspect Web Control, which includes a Business feature tier, although it might be the Firewall feature.

The Web Control feature enforces domain-level blocking across categories such as “Business,” “Cloud Storage,” or custom groups, per Avast. As Dropbox is a Cloud Storage provider, this suggests a whitelist for approved services in a Business environment is assumed by Avast.

Here are Dropbox’s official domains:What official domains does Dropbox use?

We have contacted Avast support, are investigating how we might reproduce this problem, and we’d appreciate any feedback on the results of this set of steps:

Troubleshooting Steps

Open the Avast dashboard and check the Notifications log for URL: entries.
Disable one protection component at a time to isolate the trigger (Web Shield, Real Site, Firewall).
Add the affected domain to Exceptions (enter the base domain, such as example.com, not just a page).
Restart your browser and re-test.

Additional items to check:

Firewall rules are managed under Protection → Firewall → Apps or Network Rules → Unblock or Allow connection.

Avast’s Real Site feature overrides your system DNS to prevent DNS hijacking attacks. Disabling or excluding the dropbox.com domain from Real Site may restore connectivity.

If the issue is primarily happening while working with the Desktop application, Avast documentation indicates that Behavior Shield can block background components of web-based apps if they install supplementary local services, and Email Shield can block webmail plug-ins or APIs invoked by desktop clients.

Norton

At this time, we are not certain of the feature causing the problem, but we suspect firewall related settings, or the Intrusion Prevention System features.

Norton's Smart Firewall feature actively filters all inbound and outbound network traffic and can block domains or disconnect Wi-Fi in certain configurations.

Norton 360 includes a VPN and Wi‑Fi inspection engine that monitors unsecured networks. These features can interrupt network sessions or override local DNS settings, mimicking a Wi-Fi disconnect symptom. Norton recommends whitelisting your trusted network under Settings → VPN → Split Tunneling → Add Trusted Network (link).

Norton provides some recommended steps here and also noting that “Internet Connection Sharing” setting defaults to “Block,” which can cause Wi-Fi disconnections or “no Internet access” errors until toggled to “Allow” (link included screenshots). Adjustments can be made under Settings → Firewall → Program Rules or Network Trust Configuration.

If you are experiencing issues primarily through the Dropbox Desktop application, Norton’s Intrusion Prevention System feature looks similar to a known issue with ESET’s HIPS feature (actively in progress to fix).

Norton performs deep packet inspection on HTTPS traffic, issuing its own root certificate to decrypt and inspect it. If you are seeing “Secure Connection Failed” or “Privacy Error” or ‘socket’ errors in your browser, this feature could be the issue. You can temporarily disable this feature to confirm under Web Protection → Encrypted Connections → Disable HTTPS Scanning.

We have contacted Norton support, are investigating how we might reproduce this problem, and we’d appreciate any feedback on the results of this set of steps:

Troubleshooting Steps

Open Norton Dashboard → Device Security → Settings → Firewall → Intrusion and Browser Protection.
Disable one module at a time (Firewall, SSL Scanning, Safe Web, VPN) and retry Dropbox.
Review the Security History logs under “Web Protection” for blocked domain events.
Add permanent exceptions under Web Protection → Exceptions → Add Web Address.

Here is a list of all domains used by Dropbox for reference: What official domains does Dropbox use?

All comments

Jay

Hi @Jack420, thanks for bringing this to our attention.

Could you try switching browsers to see if this makes any difference?

Otherwise, you can try using incognito/private browsing mode without any extensions running, clearing your cache and even resetting your browser entirely.

This way, we'll be able to determine where the root cause lies to troubleshoot further.

Let me know how it goes!

Jack420

Hi Jay

I tried incognito mode that still didn’t work
I deleted my temp internet files and cookies and other things that also didn’t work.
I have not tried a different browser yet. I will try that and let you know.

Dropbox works fine on my laptop and phone. I can log into drop box on all devices but the internet connection drops soon after on this affected desktop. Logging in is not required to drop the internet connection though.

I also tried to vary it up by rejecting all Dropbox.com cookies to see if that could make a difference but it doesn’t.

PatrickWalch

i experience the exact same issue. interesting and frustrating…

Jay

Do you have any proxy, VPN, firewall, security software, or even ISP/router settings that could be restricting traffic to the following Dropbox domains?

Could you try temporarily disabling them to see if this helps?

Peryton

I have the same issue for months now. But now I need to update dropbox but cannot access the website.

Please help

Jay

Hi @Peryton, could you try the troubleshooting mentioned in my earlier posts to see if this helps?

Jack420

Ok here is the update, I don’t think I am willing to try anything else as I am spending too much time on this and frustrated but maybe you can fix this for your future reference and for quality assurance.

I tried this a different browser and still had the same problem Is happening on these forums as well. I had all my firewalls turned off. Even if I reject or accept all cookies, same problem. If I initiate a log in then the problem will definitely come.

please try this on your associated PCs. There is bound to be a few that might encounter this problem. I found my storage solution elsewhere.

Mark

Jack420 wrote:
There is bound to be a few that might encounter this problem

Dropbox will have already tried, and, given only three people are reporting it there clearly isnt a huge issue with Dropbox but something (annoyingly!) very specific on either your machines/devices or your location.

Out of interest what OS and version are you using? The only time I've ever seen something like this before was when people had Little Snitch installed. Is that possible? Note I am seriously clutching at straws here!

MuhrDesign

I have the exact same problem. Every time I try to get to dropbox.com my Internet connection is lost. I had ChatGPT help me and it looks like it has something to do with my Norton antivirus software. Does anybody have a workaround? It’s very frustrating.

Mark

MuhrDesign wrote:
I had ChatGPT help me and it looks like it has something to do with my Norton antivirus software

Have you tried disabling it to test that?

MuhrDesign

I have. I disabled Smart firewall and antivirus and it allows me to login. But then after I’m logged in I lose the connection again. This only happens with my dropbox account that uses my email address. I have another account that uses my Gmail address and that one I don’t have a problem with.

MuhrDesign

Jet GPT had me uninstall Norton antivirus. That seemed to solve the whole problem, but I need Norton so I reinstalled it and the problems came back.

Jay

HI @MuhrDesign, it does sound like Norton is somehow causing this issue. Perhaps there's some kind of filtering that could disable an internet connection if certain sites are accessed, to prevent potentially harmful sites from installing programs onto your machine.

I'd recommend contacting Norton support for more information on what settings could be affecting this.

Dooney2

Same issue on Windows 11 PC, seems to have begun Sep 27 when stable build 233.4.4938 was automatically installed. Very reproducible with Firefox.

Tested again, this time with Chrome in incognito mode with cache cleared and extensions turned off, and Internet connection remained up. So at least I have a workaround. Files added through File Explorer have synced and are now visible in Chrome.

So, it looks like there’s a workaround. Whether it’s Chrome vs Firefox or using incognito mode, I’ll leave for someone else to figure out, because I have to get back to the meeting prep that this big glitch interrupted.

MuhrDesign

I decided to uninstall Norton and that cured my issues. I'll get by with Windows Defender.

Megan

Hey @MuhrDesign!

Thanks for letting us know that your issue is fixed.

We'll be one post away if you need anything else! 😇

ceezee

I don't think anyone should have to disable antivirus settings to "fix" this problem. And it IS a real problem. I'm on windows 11 and it's happened across all browsers that I've used - Firebox, Chrome, Edge. It seems dropbox has changed something which is not being viewed well by browsers and it's taking drastic action by disconnecting users from everything, not just dropbox. Please take a closer look at this and see what dropbox can do to fix this. It's being discussed on reddit quite a bit so I don't think the issue is as isolated as one might think. (Here's the link to that topic: https://www.reddit.com/r/dropbox/comments/1nmu4d5/is_dropbox_the_cause_for_my_internet_connection/)

rickoman

I am having the same problem. It's very consistent. Go to dropbox in browser, click on something - internet connection stops working.

rickoman

It's more than 3 people now...

Mark

ceezee wrote:
I don't think anyone should have to disable antivirus settings to "fix" this problem

I agree. Norton need to fix the software to stop them blocking the websites.

Nancy

@rickoman, if you’re also using Norton, can you try to whitelist the Dropbox domains as a test, and let us know if the issue gets resolved then?

SimFinance

After just opening dropbox.com, I could access IP addresses with my browser, but not domain names. I lost dns resolution. I also whitelisted dropbox.com (Norton > Security > Advanced security (login as administrator) > Safe Web > Exclusions). So far so good. Dropbox still needs to fix this.

ChatGPT gave me a temporary fix in the form of a text file named fixDNS.cmd with this content:

@echo off
echo Resetting network stack...
netsh advfirewall reset
netsh winsock reset
echo Done. Please reboot.
pause

Double clicking it restores dns resolution, but just opening dropbox.com will kill it again, whether you have the dropbox app installed or not. I hope the whitelisting provides a more permanent fix.

HalfDeathShadow

I have the same problem on win11, intel processor, AVG antivirus and VPN (but vpn is off). After visiting andy dropbox link. After a few sec. Internet on laptop is dead even that on other devises everything is going well. To restore internet i have to reset windows. I have this issue for 2 or 3 months sine today. It should be investigated

HalfDeathShadow

Update:

It seems that there is a conflict between Dropbox and AVG Internet Security. I managed to cause the internet to crash once through the Dropbox website and restore the internet by disabling the AVG firewall. I don't know how effective and repeatable this solution is, but it helped for now. Adding an exception in the firewall for the Dropbox website may help. Nevertheless, I would like Dropbox to investigate this issue thoroughly, as it could potentially affect many users.

Pajzl

I'm reporting that Avast has the same issue with Dropbox. Internet connection gets renewed as soon as I turn the shields off. It's definitely something Dropbox team should look at.

JBPage

I have been having exactly the same problem for several weeks, so your posts have been helpful. Every single time I used Dropbox on a browser - didn't matter whether it was firefox, chrome, opera, etc - the internet would cut out and I would have to restart my Windows 11 PC.

I agree with other comments - there is clearly a specific problem with dropbox, so the Dropbox team really should look into this.

I do not have Norton, so that solution was not relevant. However, I did have AVG installed. And I have now uninstalled this and the problem appears resolved.

It sounds like a few of us are having identical problems, so hopefully these comments can help to fix this permanently.

Neal

Hi everyone!

Thanks for reporting this to the Community.

In the meantime, here is the results of some of our investigations and steps you can take:

Avast

At this time, we are not certain of the feature causing the problem. We suspect Web Control, which includes a Business feature tier, although it might be the Firewall feature.

Here are Dropbox’s official domains:What official domains does Dropbox use?

We have contacted Avast support, are investigating how we might reproduce this problem, and we’d appreciate any feedback on the results of this set of steps:

Troubleshooting Steps

Open the Avast dashboard and check the Notifications log for URL: entries.
Disable one protection component at a time to isolate the trigger (Web Shield, Real Site, Firewall).
Add the affected domain to Exceptions (enter the base domain, such as example.com, not just a page).
Restart your browser and re-test.

Additional items to check:

Firewall rules are managed under Protection → Firewall → Apps or Network Rules → Unblock or Allow connection.

Avast’s Real Site feature overrides your system DNS to prevent DNS hijacking attacks. Disabling or excluding the dropbox.com domain from Real Site may restore connectivity.

Norton

At this time, we are not certain of the feature causing the problem, but we suspect firewall related settings, or the Intrusion Prevention System features.

Norton's Smart Firewall feature actively filters all inbound and outbound network traffic and can block domains or disconnect Wi-Fi in certain configurations.

We have contacted Norton support, are investigating how we might reproduce this problem, and we’d appreciate any feedback on the results of this set of steps:

Troubleshooting Steps

Open Norton Dashboard → Device Security → Settings → Firewall → Intrusion and Browser Protection.
Disable one module at a time (Firewall, SSL Scanning, Safe Web, VPN) and retry Dropbox.
Review the Security History logs under “Web Protection” for blocked domain events.
Add permanent exceptions under Web Protection → Exceptions → Add Web Address.

Here is a list of all domains used by Dropbox for reference: What official domains does Dropbox use?

Neal

Hi everyone!

As I mentioned earlier, we are actively investigating this and we need some follow up information.

Could you all reply to me and let me know if you are using Avast or Norton and specifically what version of each are you using.

Thanks!

PatrickWalch

the latest free version of avast. thank you!

ceezee

I use Norton Anti-virus. It is up to date as of today. By the way, the only way I can safely access Dropbox now on my Windows 11 pc is through an "incognito" browser on Chrome - and this even includes trying to access this forum!