Reproduction steps:
1. Open the attached “IN-116095_Repro.zip“ archived project
2. Open and change the “ReproScript.cs“ Script’s class name “ReproScipt“ to “ReproScripts“ in the 3rd line
3. Return to the Editor and wait for the recompiling to end
4. Observe the Project’s assets and the Console

Expected result: No new folders are present, no errors in the console
Actual result: “bin“ and “obj“ folders appear, a lot of “… Feature 'global using directive' is not available in C# 9.0. Please use language version 10.0 or greater.“ errors appear

Reproducible with: 6000.0.19f1, 6000.0.58f1, 6000.1.16f1, 6000.2.6f1, 6000.3.0b3
Not reproducible with: 6000.0.18f1

Reproducible on: M1 Max MacOS 15.5 (Tested by CQA)
Not reproducible on: No other environment tested

Note: If the issue doesn’t reproduce from the first try, rename the class back to “ReproScript“ and repeat steps 2-4 and so on.