Reproduction steps:
1. Open the attached “IN-116521.zip” project
2. Open the “SampleScene”
3. Enter Play mode
4. Observe the Console and the Game view

Expected result: No errors and the long text is visible in the Game view
Actual result: “NullReferenceException: Object reference not set to an instance of an object” is thrown and the long text is not visible in the Game view

Reproducible with: 6000.0.29f1, 6000.0.58f1, 6000.2.7f1, 6000.3.0b4, 6000.4.0a1
Not reproducible with: 6000.0.28f1

Reproducible on: macOS 15.6.1 (M2 Max), Windows 11
Not reproducible on: no other environments tested

Notes:
- The issue reproduces when the font asset’s “Atlas Population Mode” is set to “Dynamic” and “Multi Atlas Textures” is enabled
- If Multi Atlas Textures is disabled and applied, then enabled again and applied, the issue no longer occurs. However, if the Library folder is deleted and the project is reopened, the issue reappears. This suggests that there may be a problem with the import results
- It’s been confirmed that the issue also reproduces on iOS (on our side) and Android (on the customer’s side)