Symptoms:
- When trying to enter Play mode, I receive the error "All compiler errors have to be fixed before entering playmode!".
Cause:
If any of the scripts in your Unity project have errors that do not allow Unity to compile the scripts, this error will be displayed. You will not be able to enter Play mode until all script errors are fixed.
You are importing assets made for different Unity versions.
You are opening a sample project on a different version of Unity than the original.
Resolution:
Any compiler error will prevent you from entering Play mode. You need to look at all errors showing in the console and fix them. Double-clicking the error in the console should show you the line of code with the issue. In most cases, you can search the error message online for related solutions.
Importing assets that contain scripts can result in the above error. Check the compatible Unity versions for the asset. The code may be outdated and no longer valid for more recent versions of Unity. In that case, you must manually fix all errors or download a more recent version of the asset.
If you're opening some of Unity's sample projects, please ensure that you open these in the original Unity version. This should prevent undesired behaviors like the error in question.
If the script is not being used, you could comment on the sections where the errors appear.
If you see the error, "All compiler errors have to be fixed before entering playmode!" on a fresh project without any changes or code, please consider updating to the most recent Unity version.
After all scripts are free of errors, Unity can compile the scripts and enter Play mode.
More Information: