There have been some users getting errors on remote mounted SMB shares on the later 6.4 rc releases. Somewhere in the later release of 6.4 an new version of samba was included and has caused these and other problems. It seems that until recently, the default protocol for CIFS mounted shares was SMB v1. This is an older version of SMB and any device that speaks SMB will work on v1 without issues because it has been around so long. Because of security concerns, the Linux samba team decided that it would be best to default to SMB v3. The first issue I had to address is that not all SMB servers will use the v3 protocol, so a lot of remote mounts failed. My solution to that problem was to first try mounting a CIFS mount with v3, then v2, and finally v1. The idea was to mount the latest version of the SMB protocol that the remote server will support. This is now causing issues because of some incompatibilities somewhere. To address this problem, I have added a setting in the UD Settings so you can force all remote SMB mounts to mount with v1.
If you are having issues with errors on your remote mounted SMB shares, then change the UD Setting to force SMB v1, then unmount and remount the remote shares. I've seen some having issues with remote shares with Dockers, and stale handle errors.