One issue that we see reported occasionally is that GameMaker will crash on startup for Windows users whose PCs are being blocked from reading part of the Windows system fonts directory because a virus has created a folder in which to hide itself.
If your GameMaker is crashing each time you attempt to start it, you might have this issue, so we will cover how to rectify this problem and get GameMaker working properly again.
Note that as of the 2023.11 release GameMaker will now start showing you a dialog when it detects this situation (which may be why you are reading this page); however, all older versions will simply crash on startup. This is not a GameMaker bug, so please do not reinstall an older version of GameMaker in an attempt to ignore the dialog!
Confirming the problem
Start GameMaker and allow it to crash, then find your ui.log file inside Windows Explorer in the folder %programdata%\GameMakerStudio2\
Open the ui.log file in any regular text editor and you will see that right at the bottom of the file it contains the following lines (and specifically the top-line reason "Access to the path 'C:\WINDOWS\Fonts\Mysql' is denied."):
IDE Exception: System.UnauthorizedAccessException: Access to the path 'C:\WINDOWS\Fonts\Mysql' is denied.
at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.FileSystemEnumerableIterator`1.AddSearchableDirsToStack(SearchData localSearchData)
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.IO.Directory.GetFiles(String path, String searchPattern, SearchOption searchOption)
at YoYoStudio.Graphics.FontManager.ValidateFontFolder(String _folderpath)
at YoYoStudio.IDE.Initialise(String _args, Int32 _initialWidth, Int32 _initialHeight)
at YoYoStudio.IDE.Execute(String _args, Int32 _initialWidth, Int32 _initialHeight)
Unfortunately, having researched that error message for previous people who have reported this issue in the past, it's likely that you have a virus living in that C:\WINDOWS\Fonts\Mysql folder. GameMaker will scan the whole Fonts folder to determine your system fonts and also to load the font it will use when started-up, and whilst it obviously doesn't need anything in that Mysql folder we wouldn't add changes just to silently workaround viruses - it would be far better to alert our users to a potential issue so you can clean your machines safely, as we are doing just now.
We were looking at https://support.immunet.com/topic/3952-64exe-c64exe-serviceexe-in-cwindows/ as well as a few other reputable antivirus sites in order to gather this information originally, but if you do use an antivirus program already then we would suggest searching its own forums/FAQs for advice. This is not a new issue and you will find plenty of Google search results for other people having this problem.
Cleaning your machine
Still in Windows Explorer, if you navigate to the C:\WINDOWS\Fonts\Mysql folder you will find it's actually a hidden, protected system folder and so may not be immediately visible to you. Similarly, before you will be able to open/delete it you may need to override the user permissions for that folder.
In order to likely fix GameMaker starting up you will simply need to remove that "Mysql" folder and therefore everything inside it - GameMaker will likely then load up just fine, as the other effects of this virus are elsewhere on the system and do not affect GameMaker.
However, of course, you really should now scan your system for other elements of this virus and indeed to confirm there are no others on the machine, as we have no way of knowing the state of the system and whether GameMaker requires additional changes on your PC.
This isn't something we can offer further advice on or give individual support with (or even offer antivirus product recommendations), as it's "general IT" issue beyond the scope of our GameMaker support service. Please determine a reputable antivirus solution you're happy with and then use that to clean your machine.
Ensure GameMaker works correctly again
Resolve any potential virus issue first of all and then if that alone does not immediately fix GameMaker, then please see our guide User Permissions and Internet Access Required by GameMaker - and this guide will answer any questions about how your OS file permissions and any protection software needs to be configured for GameMaker to work properly.
Please note that whilst the guide is aimed at our educational customers and so much of the wording talks about schools and students, there is no difference to the version you are using and all advice in that guide applies to your setup also.
If you have a specific issue when following that guide, or need support with your settings to use, etc., we will have to ask you to speak to whomever typically deals with configuring the security software on your machine and/or the documentation for that external protection software, as we won't be able to help configure your machines for you.