A project produced the following error:
syntax error at line1. Unrecognized attribute (.)
What went wrong?
how to fix it?
Greetings.
Thanks Lilly:
It was our first suspicion. We work with several students and some of them advance their projects to other computers and locations. In this case, students said NO. But it may be the cause.
We reviewed the files and folder names not detect anything abnormal.
Greetings.
Did you open a project created in a newer version in an older version?
~Lilly
Maybe the best thing to do is write in to support@toonboom.com and they can help you to troubleshoot here. 
~Lilly