The Dropbox upgrade process is consistently failing on my Windows 10 (64 bit) PC. It fails silently, without any errors being displayed; a window flashes up briefly as doesn't stay long enough to be read. (This is now the third time I've enountered this issue in 3 years)! I was running on version 69 and am now (via installing in Safe Mode) on version 76. (I only use the stable versions).
The system event log says:
The Dropbox Update Service (dbupdate) service failed to start due to the following error: The service did not respond to the start or control request in a timely fashion.
It isn't affected by any antivirus or security programs on my PC (I only use Windows Defender).
All other programmes install and update correctly, so it isn't a permissions issue.
I can work around this by downloading the installer and running it in Windows Safe Mode with Networking, so it is very unlikely to be a firewall issue.
As a workaround this isn't satisfactory as the application does not update automatically, and the indications that it hasn't updated are not sufficiently noticeable to avoid it becoming unusuable before I understand that something is wrong.
I have worked my way through the diagnostic process the the support team took me through last time (except for the last step which involves totally uninstalling, cleaning up the registry, reinstalling and enduring an interminable reindexing process because I'd like to avoid that if at all possible -- and because I hope that in the last 2 years, a better soltuon has been devised!
It might be a long shot but do you, by any chance, use a 3rd party app called 'Boxifier'?
I'm only asking this as some users have reported issues similar to the one you are seeing when running this specific application.
If you have this application installed please navigate to the "Boxifier" settings, un-check the box next to "Block Dropbox updates" and apply this change.
Then, restart your computer and try replicating the issue again. If the issue persists, or you never had "Boxifier" installed on this computer, please let me know here so we can continue the investigation.