SilverStripe 2.4 accesses the obsolete TinyMCE version 2 API which was dropped in TinyMCE 3.2.6 released 2009-08-19.
Has there been any work done to upgrade SS to use the TinyMCE version 3 API?
From the TinyMCE change log dated 2009-08-19
"Removed the compat2x plugin people should have upgraded to the 3.x API by now. 3.0 was released more then a year ago."
TinyMCE is continually patched to work around countless browser bugs...
...and fix a few of its own bugs of course. So it's really important that it can be upgraded easily in SilverStripe.
SilverStripe now has a really nice clean modular interface with TinyMCE, which *should* allow new TinyMCE versions to be swapped in. However, they do not work because SilverStripe uses the TinyMCE v2 compatibility layer that has gone in newer versions of TinyMCE.
Once SilverStripe is upgraded to use the v3 API, new versions *should* be able to be dropped in because the TinyMCE developers go to great lengths to make that interface back-compatible.