Sounds like you have the machine already in the pending mode for another provisioning script to run. Make sure there are no templates slated to run on that machine and then try it again.
I doubt it's a problem with a license. From your description, your manually selecting to boot into WinPE provisioning? That's fine, but if things are working properly and you have the machine targeted for a provisioning job it should automatically boot into provisioning after you select to PXE boot.
Regardless, if it's having trouble finding the machine in the DB, you could try deleting it's current entry and manually adding it back in (name and MAC address) under Configuration --> Bare Metal Server.
I've had this behaviour when there was something wrong with the template. I had software distribution actions in the System Configuration section of my template. The package definitions pointed to a path that no longer existed. The provisioning agent counted up to 40 retries and then said it couldn't load the template - not exactly brilliant in terms of error handling. I was able to run other templates so I knew it had to be something specific with my template. By a process of elimination, I determined that it was the software distribution that caused the problem. Fixed the package source and my template worked again.
If this behaviour can be caused by a problem with a software distribution action, then maybe, other problems with individual actions (such as inject script and the script no longer exists) can cause similar behaviour. Try a really trivial template to build up your confidence again. If that works, eliminate actions from the template you're trying to get to work until the template loads...