Automatically shuts down program every time I open it

Just getting started, did the trial - liked it and the program worked fine for the first couple hours after purchase.  Now every time I open EndNote it says “EndNote X7.1 (Bld 7705) has stopped working”  then “A problem caused the program to stop working correctly. Windows will close th program and notify you if a solution is available”.   No new programs/software on my computer since it had last worked fine, tried turning off and back on, hurled profanities excessively at computer, basically none of the usual stuff worked.  I had been importing PDFs and had removed some duplicates to Trash and emptied Trash.  Went bad from there… also contacted tech support via website.

OS: Windows 7, 64-bit

Attached screen shot, albeit not likely helpful.  

Any help much appreciated

Problem seems to resolve if I remove the PDF folder from folder.  Read in a different post that it may mean I have a PDF from an untrustworthy source?  All my PDFs are from PubMed (or the subsequent medical/pharmacy journal) or are my own scans.  I’d prefer to not have EndNote decide what they think is trustworthy as it is clearly wrong… anyway I can disable this ‘feature’?