when did you last update your M&B? (there had been an update about 2-3 months ago)
Do you have steam version of M&B? ( autoupdate for M&B within steam activated?)
If not steam version did you update manualy? ( also search within the crpg forum for this as there are solutions to work around patching)
If all the former has been done more or less and you are sure that your M&B is up to date.
Have you latest version of cRPG whjich is 0.241?(hotfix!)
If yes but still doesn't work, delete again the cRPG folder and download the
full 0.241 version(not hotfix)retry, if still nothing, go to the crpg irc channel and go it through step by step with an admin or developer, i would suggest.