Error - can't save simplified articles on certain sites

[Zack B 1]

Running: Windows 7 Home Premium SP1 (64 bit), Firefox 38.0.1, Evernote WebClipper 6.0.15.

 

Was trying to save a "simplified article" note from https://hbr.org/2015/05/the-surprising-persuasiveness-of-a-sticky-noteand got the below error message (see attached jpg). Problem occurs with other articles from the same site. Does not occur when saving as article or whole page. Does not occur on other sites (tried New York Times as a test, worked fine.

 

Tried disabling, restarting firefox, re-enabling, problem persisted.

 

Tried uninstalling, restarting computer (and firefox), re-installing fresh, problem persists.