[SOLVED] Error message Execpected character in input

Hi, the following message appears as content of field document reference.

Unexpected character in input: '\' (ASCII=92) state=1 in <b>/var/customers/webs/web13/develop/model/Html2Text.php</b> on line <b>265</b><br />
Warning: Unexpected character in input: '\' (ASCII=92) state=1 in
/var/customers/webs/web13/projeqtor/model/Html2Text.php on line 265
Warning: Unexpected character in input: '\' (ASCII=92) state=1 in
/var/customers/webs/web13/projeqtor/model/Html2Text.php on line 265
-MEETREV-2-Übersicht zu Komponenten der Broker Applikation

Sometimes, the message gets longer when I save an item and when it reaches a length of 400 character, the following message appears: length for field document reference exceeds 400 characters

Could you please help me to fix this issue

The Document Name is Scan0001.jpg
There is another Version of this document called Scan0002.jpg

I'm sorry.The posted two names are the names of the document i uploaded.
I think you wanted the name of the document item. This is the name of the item.

Übersicht zu Komponenten der Broker Applikation

This is a screenshot of such a dialog
Screenshot

The PHP Version im working with is PHP Version 5.2.17

Thank you very much. Commenting out the line solved the Problem.too