Failed to save target content: Name cannot begin with the '<' character, hexadecimal value

 I use Studio 2015 freelance, and I have created a single file project, original format pdf. When saving target I get the following error message: Failed to save target content: Name cannot begin with the '&lt;' character, hexadecimal value. 

 

I tried the fixes suggested here: 

http://kb.sdl.com/?portalid=23&articleid=6797#tab:homeTab:crumb:7:artId:6797.

Unfortunately none of these seem to work for me (apparently this problem should not exist in Studio 2015).

Any suggestions? Deadline monday morning.

 

Thank you for any suggestions!

Pia