The easiest way to fix is rename the file 'CustomViews.xml' from your c:\prowin21\homebase folder to something like 'CustomViews.xml.bad'

On  next launch of ProSeries, the program will re-create the file.

For advance, you could open the above CustomViews.xml in notepad, search for the view with '&' character in the CAPTION. Note the '&' character will show up in the file as '&'. Replace/remove it. 

You should be able to relaunch ProSeries after.

I'll enter a defect and hopefully to have it fix in future release. Thanks for using ProSeries!