Yes – I am seeing the exact same issue. It reports the file saved, but no change is actually made.
Tried disabling the cache, it doesn’t work.
Running on an IIS server.
I uploaded again, but this time instead of putting the files in my webroot, I added them to a “wordpress” folder. Now the error is gone, and the TinyMCE editor shows … perhaps it’s a path issue?
I am getting this with a fresh install of 2.0.3.
I recently had 2.0.2 running – with no error, and the WYSIWYG editor was working. I wiped clean that install, and did a clean install of 2.0.3, and only now get the error.
I get it in both IE and Firefox.