One Drive - File Name(s) too long for the destination folder.

One Drive Limits the number of characters a file name can have, the folder structure that the file sits in, also counts toward this limit. The limit is 400 characters.

Example: L:\staff\users\jane\documents\New Work\2020\Jan\testfile.pdf (All of these characters count toward the file name in the cloud)

If you can shorten the names on files and folders it could get it down enough to allow the files to sync.

You might have to get a little creative with your abbreviation, instead of Reconciliation shorten to recon, instead of Head Start - HS

As soon as it gets shortened to 400 characters or less, the sync will go through. (Otherwise the file just stays on your local computer).