I am a newcomer to Duplicati. Here is my problem: after a new, fresh install of Windows 10 I usually now get about 2000 warnings from a Duplicati backup. The warnings are all connected to missing access rights to directories in the main Windows directory. How to get rid of this annoying behavior?
Sounds like you may have selected your entire C: drive for backup. I would not recommend this. Instead just back up your user data (documents, pictures, etc). Duplicati is not suitable for image level / operating system restores so it’s pointless to back up those locations.
If you still really want to, you will probably need to run Duplicati with elevated administrator rights and enable VSS snapshots. This should allow it to back up everything on C:.
I’ve seen many people also backing up browser cache and all other temp junk, which is totally pointless and just makes backing up data slow and bloats backups. Don’t backup cache and temp directories in general.