Ok, i found the bug, and fixed it for the next beta. Thank you for reporting.
Anyway, IF you are putting your macros in the diff template dialog, just know that it is going to never work, from now on.
It's a security measure: nothing in the virtual file system will be allowed to contain macros.
The risk is that .vfs files (those where your virtual file system is saved) could become just like MS Word .doc, and carry malicious instructions.
What you can do is to put your macros in external files.
For real folders, you can put your file just inside the disk folder, and name it "hfs.diff.tpl".
For virtual folders, you can put your file anywhere, and enter the full path (a single line) to the file in the diff tpl dialog.