I’m having the same problem but the backup file is created in my backup-db folder so I’m not too worried.
I contacted my administrator about the error and his reply was:
“Yes, it looks like a bug. The problem stems from using file_exists() outside of the open_basedir to check the paths, rather than just calling exec() and returning an error only when that fails.”
I don’t know if that helps or not because it’s beyond my technical skills.
