I've been using Dropbox on different MacOS machine for many years (iMac and MacBook Air).
One iMac (Sequoia OS) and one MacBook Air(Mojave OS) both run fine with dropbox version 237.4.5655 perfectly (desktop application launch, syncing...).
Another iMac (Mojave OS) has also been running fine for years with dropbox version 194.4.6267 but suddenly will not launch the application since a few days now.
What can be done so version runs again ?
Thank you in advance for your time