Steps to reproduce:
1. Open user provided project. Notice 'ArgumentException: Illegal characters in path.' in console
2. Open 'Editor Tests' window (Window > Editor Tests Runner). Notice it says 'No tests were found' even though there is a test script in 'Assets/Editor'
3. Open playerSettings and delete ' | ' character from Product Name
4. Change platform or reopen project
5. Notice there is no 'ArgumentException' in console and test runner finds test script

Reproduced on: 5.3.6p7, 5.4.0f1, 5.4.2f1, 5.5.0b8

Characters that reproduce the issue: | " < >