Unicode error in Plone resourceditor

Plone Support Theming
3

The unicode errors comes from the resource-editor javascript.
Will check when I am back...
Failed to load resource: the server responded with a status of 500 (Internal Server Error)

And when I click on it:

{
"error_type": "UnicodeDecodeError"

}

The error log shows:

Traceback (innermost last):
  Module ZPublisher.Publish, line 138, in publish
  Module ZPublisher.mapply, line 77, in mapply
  Module ZPublisher.Publish, line 48, in call_object
  Module plone.resourceeditor.browser, line 583, in __call__
  Module plone.resourceeditor.browser, line 533, in do_action
  Module plone.resourceeditor.browser, line 226, in saveFile
UnicodeDecodeError: 'ascii' codec can't decode byte 0xce in position 3673: ordinal not in range(128)

Looking at the change-log I see that this is supposed to have been fixed in version 3.0. I think I had some other problems when using 3.0 on 5.1.5, maybe I could try to downgrade to 2.1.1