Nothing specifically. can you try something for me? I have uploaded a zip file which contains a file called designerlauncher.l4j.ini inside of it. can you place that file next to the designer launcher executable? Make sure its specifically the executable, not the shortcut (if you right click the shortcut you should be able to click Open File Location which will show you the original designerlauncher.exe file.)
designerlauncher.l4j.ini.zip (244 Bytes)
Once that is done try launching the designer launcher. It should look like this: 