All of a sudden, can't add new hot key triggers anymore

Questions & Suggestions
1

No idea why I can not add a new hot key trigger in the «Type» field anymore.

Any ideas what could be wrong (with me)?

Grateful for every suggestion -
Walter

2

Added by myself: A restart (Mojave 10.14.3) solved my issue.

3

This is one of the first things to try when you are getting very unexpected behavior.