I'd love to help, but unfortunately there s little I can do. Yate does not directly access files for reading or writing but rather goes through the OS for all file access. That's the only reason that external mounts and file systems provided by plugin support will work. In both images I can see that Yate got a read error, which implies that the OS got a read error while accessing the file and passed it up. Read errors can happen when saving, as a Save operation requires rereading a portion of the file after a write.

There are obviously some connectivity issues. Most operations such as Finder copies read the file in its entirety and it is possible that the driver favours streaming. Yate definitely accesses files by seeking around the file and only reading the necessary data. All of my files are on a NAS drive and there are no issues accessing them. This might be a driver implementation issue.