Error message – Cached credentials need auth

This answer is valid for IDEA StatiCa version 21.1. and older versions

If you got this error message, your credentials for the license activation in your system cash are most probably damaged. 

You can solve this issue quickly by deleting the Shafer folder located in C:\Users\%USERNAME%\AppData\Roaming\IDEA_RS

When you delete the folder, you can try to sign in again.