JobTempAlloc has allocations that are more than 4 frames old

Well it seems you've found one of Unity's leaks. Somewhere in LoadLevelSystem.cs there is an allocation that should be marked as Persistent instead of TempJob.

 

Application. targetFrameRate = 120. As posted earlier in the forum fixed the problem for me.

I was in a scene that only had a UI with it, so I was getting like 1400 fps. That apparently was causing issues. Limiting the fps solved it

 

Having the same issue... I'm on 2019.4.4f1 and I don't use any jobs system. I really don't know what is causing it... It is my codes or something internal because the log isn't telling me the cause.

 

This answer worked for me. Thank you.

 

I got this warning when I used [UpdateInGroup(typeof(ServerSimulationSystemGroup)] attribute while working with EntityCommandBuffers.
Removed the attribute but still got the warning, even in an empty scene.
Created a new project all together, sample scene worked but once I re-downloaded and imported ECS packages, I got the warning.

Then I came across Application.targetFrameRate=120; It fixed it but It feels more of an hack not a fix.

My version is: 2020.2.2f1

 

I faced the same, and it turned out I had ~200 objects doing OnDrawGizmos using transform and a bunch of lines. This caused the editor to slowly build up garbage and enter crawl-mode. Unity 2018.4.23f1 (because enlighten rules and zuckerbergs VR sucks!).

Replying here because this was the first hit