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Why Is Cura Not Opening? 2 Common Causes and Fixes

Unfortunately, Cura not opening is a common problem you can run into with the software. However, there are many reasons that it might not open.

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Unfortunately, Cura not opening is a common problem you can run into with the software. However, there are many reasons that it might not open, making it difficult to know how to diagnose the problem and fix it. Still, if you know all the probable causes and how to fix them, you’ll never have an issue again!

Cura won’t open when it’s incompatible with your operating system or graphics card. You may want to update your PC or use an older version of the Cura software. Cura might also fail to open if your antivirus blocks it, though this issue is much less common.

This article will discuss the most common reasons Cura won’t open on your PC. Plus, I’ll also go over all of the fixes so that you can get back to 3D printing. Everything you want to know is below, so let’s get started!

1. Cura Isn’t Compatible With Your Current PC

In most cases where Cura won’t launch, it’s not compatible with some aspect of your PC. Most of the time, Cura will have issues with either your operating system or your graphics card. If you have an old operating system or old computer, you’ll have to make some changes.

Newer versions of Cura usually have fixes built-in for these issues. However, if you’re running 4.4 or lower and Cura won’t start, you’ll need to use the directions below to fix it.

Overall, Cura not being fully compatible with your computer is the most common issue. I recommend that you start here when trying to fix it. If Cura still doesn’t work, then move on to troubleshooting using the information below.

How To Fix Incompatibility With Operating System

If you’re using Windows 8 or 10 and Cura doesn’t want to start, it’s likely not compatible with that version of Windows. Cura no longer supports Windows 7 and lower, so you’ll need to upgrade your operating system if you’re still using that version and it won’t run. 

If you’re using Cura 4.3 or 4.4, you can launch it using Windows 8 compatibility mode. This mode allows the program to run with Windows 8 and 10. Here’s how you can do that:

  1. Open the directory where you saved Cura.exe when installing. You likely can find it under C:Program FilesUltimaker Cura 4.3 in your system directory.
  2. Right-click on the Cura.exe file and select Properties. There you will find the Compatibility tab.
  3. Inside the Compatibility tab, find the section that says “Run This Program in Compatibility Mode For:” and select the Windows 8 box. Select “Ok,” when prompted, then run the program like usual. The program may ask you to run it in admin mode, which is fine.

Most of the time, this process fixes Cura not launching. However, Cura may not be completely compatible with other areas of your computer if it still doesn’t start after changing the compatibility mode.

How To Fix Incompatibility With Graphics Card

According to Ultimaker’s minimum system requirements for Cura, it requires a graphics card compatible with OpenGL2 or OpenGL 4.1 for 3d layer view.

If your computer doesn’t boot Cura, the GPU or graphics card might be the issue. You can check what graphics specs your PC has by using the following steps:

  1. In Windows 10, go to Task Manager at the bottom of your screen.
  2. Open the Performance menu, which may appear under “More Details.”
  3. You’ll find the GPU brand and model in the top-right corner of the Task Manager.

Compare your graphics card with what Ultimaker requires for Cura to run. 

If yours is too outdated to run the software, that could be why the program won’t start up anymore. You can consider replacing the graphics card on your computer. If you aren’t comfortable doing that on your own, you can have a professional assist you.

Overall, keeping your GPU up to date will help Cura run smoothly. If your computer is old, the chances are that the hardware will begin to struggle with running programs such as this, especially as Cura releases newer updates. 

2. Your PC’s Antivirus Blocks Cura From Opening

In some cases, your computer’s antivirus software might be preventing Cura from opening if the antivirus interprets Cura as malware (don’t worry- it isn’t!). You’ll need to adjust your firewall to get it working.

How To Fix

Your antivirus is likely blocking one of these three executable files:

  • Cura.exe
  • CuraEngine.exe
  • CuraCLi.exe

You can make custom settings for those files in your firewall so that they’ll run again. However, how you do that depends on the antivirus that you use. 

For Windows Defender, open the Windows Defender Firewall and navigate to the Advanced Settings Menu. Then, do the following:

  1. Go to Inbound Rules and Outbound Rules. Delete all instances of the above executable (.exe) files. Then, close the window to save.
  2. Go to Change Settings in the firewall and select Allow an App through Windows Firewall or Allow another app. Select Browse, then go to C:Program FilesUltimaker Cura.
  3. Select Cura.exe to add it to the programs through the antivirus firewall. Add in CuraEngine.exe and CuraCLi.exe as well.

Using these steps will stop your firewall from blocking the files that start Cura. After adding those files, you should start up Cura successfully and smoothly every time!


There are a few common reasons why Cura won’t open. Suppose you can figure out what’s preventing Cura from running on your computer. In that case, you can easily make the adjustments to get it going again. Sometimes upgrading to the newest version of Cura is all you need to do to fix it.

I understand how frustrating it can be, but just make sure you try the above fixes first since they’re the two most common issues you’ll run into. If you follow these steps, you’ll likely have the program up and running again in no time!

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About Ben

I started 3D printing since 2013 and have learned a lot since then. Because of this I want to share my knowledge of what I have learned in the past years with the community. Currently I own 2 Bambulab X1 Carbon, Prusa SL1S and a Prusa MK3S+. Hope you learn something from my blog after my years of experience in 3D printing.