Project locked after printing

I am having some trouble in LL12.

I can call up a project file into the designer and exit and go back in as many times as I like, but if I have the project print, I can no longer access the project in the designer as the file is locked.

Is there a call I can make that will release this?

I searched the FAQ and forum prior to posting.

Thanks,
Gary

Perhaps you forgot LlPrintEnd in your printing code?

No, that part is there, and I also made sure to end the print job if there was an error.

I discovered that I can print as many times as I like. After the first time printing, I can no longer open the project in the designer until I restart my program.

I can go in and out of the designer and many times as I need to but as soon as I print I can no longer access the project in designer.