Unity won't build my game and keeps reloading

For some reason, every time I try to build my game to send to some people i’ve gotten to help playtest, unity starts the processe then makes an error noise and says “Cannot build player while editor is immporting assets or compiling scripts”, how do I fix this issue?

Obviously, if there is actionable data, clues or information within any of the errors, fix those problems. Each error entry may have more information than can fit in the console log so select each error and read the expanded view below it.

If that gives you nothing worthwhile (look to Google! You’re never the first one!), then…

First, make a blank project with a single blank scene and prove that it builds successfully.

If the blank project does NOT build, go fix your Unity installation or your other tools, such as Android SDK, NDK, JDK, etc. It may even be necessary to change to a different version of Unity3D. It is generally best to stay with LTS versions of Unity3D.

Until you can build a blank project to the target platform, don’t fiddle with anything else.

Once you can build a blank project, now bisect the problem by bringing over parts of your current project and building it one subsystem at a time, perhaps stubbing things out that might trigger compiler errors.

Most often things that prevent building are misconfigured or incorrectly-installed or incompatible third-party libraries such as Firebase or AdMob or IronSource.

Once you identify the subsystem, go to the documentation for it and make sure you are doing it correctly.

It may also be helpful to work through a tutorial or two for whatever subsystem is making the build fail.

Android build not building:

Circa July 2022 here have been reports of Unity’s installer failing to install the Android Tools.

Here was how I brought up Unity2020.3.41 and the Android SDK 31 on October 30, 2022 (edited on August 23, 2023 to include Android SDK 33…) (and again for SDK34):

Android Gradle errors and other related stuff:

Android SDK35 stuff:

This COULD be caused by a broken editor script.

Imagine something hooking into one of the many editor events which occur during a build, like domain reload or the actual build process starting. In there, such as script could do something innocuous like modifying some assets (including scripts) and then calling AssetDatabase.Refresh which would trigger Unity to reload assets, import them and possibly recompile.

And then that’s the message you’ll be getting every time you try to build.

Try making a copy of the project and start stripping out primarily editor scripts or assets that are editor tools until you can narrow it down to the cause.

Turns out, I just needed to restart my computer, no idea WHY this worked, but it did.

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