Unable to sync file due to server error

Every day I get the same message on my iMac saying that Creative Cloud is unable to sync one particular pdf file that I had deleted already.

To try to solve the issue, I deleted the pdf file from my Creative Cloud file and also deleted the associated indd file.

Subsequently, I permanently deleted the files from my Creative Cloud web folder.

Then I deleted the pdf and associated indd files from my iMac.

Further, I uninstalled Creative Cloud desktop app, then reinstalled it. When that didn't work, I uninstalled and reinstalled again.

Yet according to the desktop Creative Cloud app, this one ostensibly non-existent pdf file is still "unable to sync due to server error" and I still get the red warning icon on the desktop app and its associated error message.

This only happened on my iMac (OS X, version 10.11.6) but not on my MacBook Pro (same OS and version); all assets on my MacBook sync without a problem.

I checked the forums and no other discussions seemed related to my particular issue. Any thoughts?