invalid comment declaration: found character %1 outside comment but inside comment declaration

Cause:

Check that you are using a proper syntax for you comments, e.g: <!-- comment here -->. This error may appear if you forget the last "--" to close one comment, and later open another.

Example:

textexample textexample

Bad:
textexample
textexample
Good:
textexample textexample

Solution:

textexample textexample

References: