When a question has been edited in MathQurate, the resulting file has each block of Maxima code repeated inside the CDATA section of the customOperator. This is usually non-critical in ScriptRule calls - it just makes it do the whole calculation twice! However, if the customOperator is CasProcess or CasCondition, it kills the question because CasProcess and CasCondition expect a single command.
I'm sure I've mentioned this before, but since many questions just use ScriptRule it is usually not a great problem. Trouble is, I now have a group of questions using CasProcess and they are broken if I go into MQ, so I can't package them.
Differentiation question with repeated Maxima