I have been having trouble syncing files for a while.
I kept getting an error message saying 'Unable to sync <Filename>' which was a file I had deleted weeks ago. In an effort to rectify this and to clear space on my SSD I tried moving my storage to an external HD.
This didn't work and was too slow so I attempted to move the target folder back to my device SSD. However, when I did this all my sharing rights to files I was using with my business partner were lost. I asked him to send me invitations to the files again and in order to ensure the target file was not the problem I tried to save the newly shared files in a new folder.
However, this sync did not work and now I get nothing but error messages saying it is not able to sync to the file. Everything I need is on the cloud so all I want to do is reset all my defaults and gain access to the 8 folders I was invited to at 9.28-9 this morning (09/11.2019)