After Windows 7 Update, Corel Video Studio Pro X6, X5, X4, X3 will not open; it won't run - Here is the fix
For many users of the older versions of Corel VideoStudio Pro such as X6, X5, X4, and X3 we were surprised and annoyed in February 2016 to find that the program would not open after downloading the latest batch of Windows 7 updates. A solution to the immediate problem was soon posted - remove Security Updates KB3126587 and KB3126593. I suspected that something similar could happen again with another release, and sure enough it did in September 2016. Searching the internet, I found up to 8 more Security Updates identified as interfering with the program, but this time removing them did not work for me. However, a more permanent fix appeared in the 16th and 17th pages of a forum on the topic, and all credit goes to them. So that you do not have to dig it out yourself, I am posting it here. Corel has apparently decided not to provide hotfixes for versions of VideoStudio older than X7.
1) Find your VideoStudio program file on your computer. Mine is in OS (C:) - Program Files (x86) - Corel - Corel VideoStudio Pro X6. Click on it to show all its files.
2) When you scroll down past all the file folders, the individual "application extension" files etc. are listed alphabetically. Find the one named MUIHelper.dll and rename it MUIHelper_old.dll
3) Download the corrected MUIHelper in a zip file from the forum page
4) Right click on the small zip file and move to "open with". If you don't have WinZip, you have the option to open it with "Windows Explorer". Move and paste this MUIHelper into your program. It should show up just above MUIHelper_old.dll
Your VideoStudio program should now open. It seems to be immune from interference from Windows Security Updates. We shall see if that lasts.
John Michael Fischer, October 25, 2016