"Access is denied" when executing "Copy File" in Hammer compile

Since moving my games over to a new SSD, Black Mesa’s Hammer doesn’t seem to want to work properly. I gave Black Mesa a fresh install for the new drive, so I thought it would be fine, but no luck.
On a fresh install, all of Black Mesa’s expert compile options in Hammer are blank, and after copying them over from another game, it all works fine except for “Copy File”.

It keeps giving me an “Access is denied” error. The map itself is compiling fine, but it just can’t copy the map file to the maps folder for some reason.
When using non-expert compiles it works perfectly, and I double checked over all of the settings I put in for Expert and nothing is off. They’re the same options I use for Portal 2 and were the same as in HL2 as well.

And of course, I’ve scoured multiple pages on Google with varying search criteria, and no luck. Anyone know anything about this, or do I just have to make bms/maps the home for my VMFs so that it doesn’t have to copy anywhere?

Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valve’s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.