Laureen, do you happen to have a previously-created PDF of awards forms open in Acrobat Reader? I've found that I have to close that PDF file in order to have a new one opened by BLS (but Acrobat can open multiple PDFs--it just can't generate a new USBC from BLS with one already open).
You didn't mention the version number for Acrobat Reader. I suggest updating it as even that might be in play here.
Always check, download, and install the most recent update of your software to ensure that issues may have been corrected.