Thank you for your reply, below are the answers to your questions.
I forgot to mention that I always use row editing mode.
1. Yes, if I have a textarea filled with multiple lines, it does not work, also when I only have a single line typed into the textarea. Should the umlaut be the first character in the textarea, then the editor stays open and the validation says missing input and I cannot leave the field... -
If I have a simple textbox, everything with the umlauts is fine - it's only the textarea, which is making problems, regardless how much lines it has.
When I enter the umlauts directly in the database and then load the grid, they are displayed correctly and also saved again right. But I still cannot enter new ones...
2. I did not use height: 'flex' or flexHeight:true - height of my grid is 250 (fixed value in the grid object configuration)
3. I (and the users of my application, too) use Firefox. I tested with version 40.0.3 and updated to 41.0.1 - the error occurs in both versions. In Opera 32.0 the textarea works fine. I did not test Internet Explorer, because it is not relevant to us - everyone uses Firefox, most recent version (scheduled updates).
4. In daily work, the users type in umlauts (ä, ö, ü) a lot, so they noticed the error.
When I enter an apostrophe it will be saved via ajax and displayed correctly in non editing mode. When I then reload the complete page and open the textarea for editing, the hex declaration ''' is shown instead of the apostrophe, leaving the edit mode displays the normal character again. I did not recognize issues with other characters yet (ß is working fine for example).
5. Thank you for the link to the previous version. In version 2 demo it's the same behavior like in 3.1.0.