Unity Errors After Upgrading Editor Version

How to fix it

Try these in order — the most common fix is first.

1. 1. Back up and use version control

   Copy steps
   1. Commit or copy the project before upgrading
   2. Upgrade a copy first and test
   Did this fix it? Yes No

2. 2. Update packages and plugins

   Copy steps
   1. Open Window > Package Manager and update packages for the new version
   2. Re-download Asset Store plugins and check their supported Unity versions
   Did this fix it? Yes No

3. 3. Fix API errors

   Copy steps
   1. Accept the API Updater prompt when it appears
   2. Search the error text in Unity's upgrade guides and fix the renamed APIs by hand
   Did this fix it? Yes No

4. 4. Go step by step

   Copy steps
   1. Upgrade one LTS version at a time instead of jumping several
   2. Use Safe Mode to open and fix scripts if the project will not load
   Did this fix it? Yes No

Symptoms

After opening a project in a newer Unity, the Console fills with compile errors, packages are missing, or the project will not open in Safe Mode.

Why it happens

• Deprecated or removed APIs
• Asset Store plugins that are not updated
• Package versions not compatible with the new Editor
• Changed render pipeline or input defaults
• Skipping several versions in one jump

This guide also covers

• unity errors after upgrade
• unity upgrade broke project
• unity project won't open after update
• unity safe mode

Other Unity errors

• Unity Hub Not Opening
• Unity License Activation Failed
• Unity Editor Crashing
• Unity Build Failed
• Unity Android Gradle Build Failed
• Unity Package Manager Errors
• Unity Slow Compile and Domain Reload
• Why Is Unity Editor So Slow