Why are you using MPLAB? If it's just to write your code then compile, you may try MicroCode Studio. There's a free version available on the following link
http://www.rentron.com/mcstudio/mcs2300.zip

I hope this will work... Of course an update will be a smart choice. I'm just surprised about the MELABS's answer

You can still use the usual, remove everything, and reinstall everything + the MPLAB plug-in