So we were having an issue with Folder Redirection today with a user. We were moving them from a fileshare to a UNC path. The difference is a file share is explicitly shared, the userdirs$ is a share that then has a folder within.
This was the error in fdeploy.log (enabled here).
16:32:10:116 Homedir redirection path %HOMESHARE%%HOMEPATH% expanded to \newserveruserdirs$user1. 16:32:10:116 Redirecting folder My Documents to \%HOMESHARE%%HOMEPATH%. 16:32:10:116 Previous folder path \oldserveruser1$ expanded to \oldserveruser1$. 16:32:10:116 New folder path \%HOMESHARE%%HOMEPATH% expanded to \newserveruserdirs$user1. 16:32:11:007 Failed to perform redirection of folder My Documents. The folder is configured to be redirected from <\oldserveruser1$> to <\newserveruserdirs$user1>. The following error occurred: %%26
%%267. After some brief investigation it was found this users had a huge My Docs and it was copied to the new server. The old directory was then renamed (user1.old) and a new directory was created called user1 and reshared as user1$ on the old server. Then this issue occurred. The reason this issue occurred was because the user wasn’t assigned any permissions on the old directory so it was erroring out. I don’t know if %%267 is a permission code or not but that’s what we found. By adding the user to the folder \oldserveruser1$ as full control did it then proceed and migrate his My Docs correctly.