Reproduction steps:
1. Create and open any new project
2. Go to Edit > Preferences > General
3. Make sure “Editor Font” is set to “System Font”
4. Go to the Package Manager (Window > Package Manager)
5. Install the “Unity UI” package
6. Go to Window > TextMeshPro > Import TMP Essential Resources and import everything
7. Close and re-open the project or click Reimport All (Assets > Reimport All)
8. Observe the Editor

Expected result: All Editor text is rendered correctly and no errors in the Console
Actual result: Parts of text in the Editor (particularly visible in Package Manager) are rendered incorrectly or blank, and “Can't Generate Mesh, No Font Asset has been assigned.”, “Unable to load font face for [System Normal]. Make sure "Include Font Data" is enabled in the Font Import Settings.” warning logs are shown in the Console

Reproducible with: 6000.0.45f1, 6000.0.46f1, 6000.1.0b14, 6000.2.0a8
Not reproducible with: 2022.3.61f1, 6000.0.44f1

Reproducible on: Windows 10, Windows 11
Not reproducible on: No other environment tested