Fixed this issue on 2017.3.0f3. Toggled off Crunch Compression on all images, then deleted Library and UnityPackageManager. When I switched platform to Android again, the error was gone.

I got this error after switching my project to android and building a apk, unity 2017.3.0f3

**Update**
Dang, that is, it actually stopped the error as I was running the Windows platform in build settings. Once I switched back to Android, the issue came back.

I fixed this issue by deleting the following folders in my project:

/Library
/Temp
/UnityPackageManager

I restarted, and the error did not spawn any longer.

Before this, I tried Bilgisoft's solution which did not help.

Does anybody solved this issue?
I did not find any solution for the building problem for iOS in Unity also by installing the most recent patches released by Unity team

Thanks to everybody

In 2017.3.1f1 I am seeing this error when setting "PlayerSettings.iOS.iOSManualProvisioningProfileID".

Repro'd on both Win10 and Win7.

Everything seems to continue to work fine but, once this has occurred, editor updates will cause the messages to spam the console, requiring a Unity restart to clear.

In my previous comment what I meant with "they don't clear their native arrays in the process" I meant Unity

It happens on Unity 2017.3.1p1
fresh project -> build for iOS -> TLS allocator error afterwards.

It is incredibly annoying if you want to build and then debug some things in the editor because the log is getting spammed. So even if it is a "minor / comestic" issue, it is interfering with debugging.
Slowing down debugging after a build for iOS.

For those who said removing crunch compression works. Thats a seperate TLS allocator issue.
They probably don't clear their native arrays properly somewhere in the process.
I did not have this issue for Android builds when using crunch compression for ETC2.

Same.. please fix :)

This occurs in the editor regardless of platform. And it never used to happen but started happening more recently.