Step 3: Navigate to Apps and features

Step 4: Select Paint 3D
Step 5: Click on Reset
After this, all steps try to reuse your Paint 3D application. Surely it would help you out. But yes, your settings which you made so far in Paint 3D have been reset either, so you need to make the settings again.
But still, if you think that Paint 3D is not working well still, then you can for another fix.
Fix 2: Re-install Paint 3D
Yes, you can reinstall Paint 3D in your Windows 10. You just have to follow this below steps to re-install your Paint 3D.
Part 1: Uninstall Paint 3D
First, you need to Uninstall the Paint 3D app from your computer.
Step 1: Open Setting
Step 2: Navigate to Apps and Features
Step 3: Browse to Paint 3D
Step 4: Click Uninstall Paint 3D

After this, your Paint 3D has been uninstalled from your computer successfully.
Part 2: Installing Paint 3D again
Now after uninstalling your Paint 3D application, you can Install that again by going this method.
Step 1: You can simply click on this Paint 3D, or you can search Paint 3D in Microsoft App Store
Step 2: Select the Paint 3D
Step 3: Click on Get

After that, wait a little while till it installs on your computer according to your broadband speed, and it will Install the Paint 3D on your computer.
You can try your Paint 3D now, and still, you are facing those crashes, then you can check the next Fix too.
Fix 3: Troubleshooting Windows 10
So if you went through both fixes with the Paint 3D, but still no method worked for you, then it is an issue of your Install Integrity issue. So you need to get in some more technical way and Troubleshoot your Windows 10.
Step 1: Restart your window 10 computer
Step 2: Hold the Shift key and press the power or restart button in the corner.
Step 3: After when the computer starts, select Troubleshoot.
Step 4: Click on Advanced Option
Step 5: Select Startup Settings
Step 6: Click on Restart
Now, after this, your computer restart from itself. This will also help you to resolve some other issues going on your computer.
Conclusion
In the above fixes, you will surely get your work done. Now, after this, you know what wrong going in your application. You can also try on other applications if they are behaving the same as this.
Sometimes error of code can lead to this type of problem in your computers, so you need to fix your error by yourself, and there is no rocket science in the above fixes, which are usually quite easy to follow, and it will surely help you to resolve your issue.