Hi,
You can try the steps given in the article to remove Muse completely from your system. Try Solution 2.
http://helpx.adobe.com/muse/kb/unexpected-error-occurred-i-200.html
Once you have done this, download the new version of Muse given in the same article, and it should be fine.
You can also try to run CS cleaner tool which can be found here
http://www.adobe.com/support/contact/cscleanertool.html
Hope this Helps