I've noticed that Dropbox has been failing to upgrade from v112 to v113 last week. I've decided to uninstall it and try installing it manually, but the installer would stop with "Error 2" (v114 is also affected). Reading up on it I saw that that error means the issue is outside of Dropbox's control. I've dug up the installation log file and saw that it ends with
File "ssl.pyc", line 482, in _load_windows_store_certs
ssl.SSLError: nested asn1 error (_ssl.c:4034)
which for me was (un)fortunately a known issue. I am from Serbia and this error is common for Python when there are government certificates (for reading government ID or driver license smart cards) installed on Windows. In order to have these on the computer you have to install them manually from the government's website, but many people / offices will have them so I suspect many people will be having problems with Dropbox until this is resolved.
I've solved it by removing the certificates (search for "Internet options" in Start menu, go to Content > Certificates, look for everything that looks like it has to do with Serbia - I deleted one from "Personal" tab and one with name starting with MUPCA from "Intermediate" tab). Of course, do this at your own risk if you know what you're doing, I deleted them since I don't really need them. After deleting these Dropbox installed without problems.
Feel free to forward this to Dropbox engineers because I know a bug like this can be a hell to debug and they'll be grateful to be aware of this. Something was changed after v112 since Dropbox worked fine on my machine for months/years. This is a known issue (with a known workaround for local Python installations) https://bugs.python.org/issue35665.
