Bug? Access denied error when compiling

I keep repeatedly getting this error when compiling with B4A v9.30. I don't recall getting it with earlier versions.

B4A Version: 9.30
Java Version: 11
Parsing code. (0.03s)
Building folders structure. (0.01s)
Compiling code. Error
Error compiling program.
Error description: Access to the path 'C:\Users\Andy\Documents\B4A\Projects\Examples\TableExample\Objects\src\anywheresoftware\b4a\table\main.java' is denied.
Error occurred on line: 162
End Sub

Click to expand...

Retrying the compilation succeeds but this happens often enough to be annoying. I assume it is probably something to do with auto-backup, but the IDE should know this is happening and maybe wait, or do a retry or two or flag that it is starting a compile and not to start a backup.

It is not related to auto backup. I also don't think that it is related to B4A version.

Is it possible that Windows Explorer is open on this folder?

The folder containing the generated Java files? No.

Use Process Explorer and find out which program locks this folder: https://docs.microsoft.com/en-us/sysinternals/downloads/process-explorer

I don't think that will find it as whatever has it locked only locks it briefly because an immediate recompilation always succeeds. As far as I know Process Explorer can only find current locks, not historical ones.