Protected Garmin file toolkit 2.3.0.4 x64

I'm using the tool to try to unlock a Garmin gmapupdate.img for use as a gmapsupp.img file in another Garmin NUVI that does not have a lifetime update subscription. However, the tool issues an error message that it cannot access the file even though it is in the same folder as the tool. What is the solution?

Never mind. I found the problem. The file had the read-only attribute set. When I cleared it, the tool worked without issuing an error message.