I had similar problems until I created a new Windows user account and opened 12 and 13 there. Now both work as they should.
I think my old account became corrupted perhaps because of some of the anti-malware, directory repair and other software.
I had also downloaded Advanced and had 12, 12A and 13 running in one account.
Creating a new account is almost like a new computer. I try to only use it for FileMaker so I don't have to go through all of the steps needed to gain access to this and that.
I had assumed it was open because I thought that was the port used for general access to the databases but i see that seems to have changed. I'll have IT check on the port situation.