If you are running Windows 10 and Cura won’t launch then in most cases all you have to do is run it in Windows 8 compatibility mode. And if that doesn’t work there is an additional step you’ll have to take to configure your firewall. And then if you STILL aren’t able to launch Cura you’ll need to temporarily disable AVG antivirus by clicking the up arrow at the right corner of the Windows screen, right clicking on the AVG shield icon, and sliding the “Protection is On” button to off. Then launch Cura and re-enable the antivirus.
Step 1: Go to the directory that stores the cura.exe which will probably be C:\Program Files\Ultimaker Cura 4.3
Step 2: Right Click on the file named Cura.exe and go to Properties
Step 3: Click the Compatibility tab and check the box which says, “Run This Program in Compatibility Mode For:” and make sure Windows 8 is selected. Click ok and run the program either from that directory or from the normal shortcut. Fixed! In some cases you’ll have to run it in administrator mode, but usually not.
Now if that STILL doesn’t fix your problem the problem is the windows firewall is preventing the Cura.exe and CuraEngine.exe and CuraCLi.exe from initializing. This is easy to fix. First we’ll have to make sure no custom firewall settings are set for those files.
Step 1: Hit the Windows button on your keyboard and type “Settings” and hit enter. Then in the search bar type “firewall” and go to “Windows Defender Firewall” and go to “Advanced Settings”.
Step 2: In “InBound Rules” and “Outbound Rules” make certain there are no custom entries for Cura.exe CuraEngine.exe CuraCli.exe or anything that says something like CuraSlicer or SlicerEngine or CuraEngineSlicer or whatever combination of words. If there is just delete those entries. We’ll set the rules for those programs in another way in the next step. Once they have been removed close the window.
Step 3: Go back to windows settings and in the search engine type “Allow an App through Windows Firewall” and hit enter and in the window that pops up click “Change Settings” and then click “Allow another app” and click “Browse” and go to “C:\Program Files\Ultimaker Cura 4.4” which is the default install directory for Cura 4.4. Obviously if you are using a previous version go to the correct install directory for that version.
Step 4: Once you’ve done this select the Cura.exe file and open it and click “Add” which will allow it through the firewall. You should repeat this for CuraEngine.exe and CuraCli.exe however you may not need to.
Step 5: Now simply setting Cura.exe to run in Windows 8 compatibility mode with or perhaps without administrator privileges as discussed before will work just fine. Enjoy!