gpg2 - Unusable public key -No assurance key belongs to named user

I'm using pass as my main password manager(which uses gpg2), but since a few days i can't create new keys, I always get the error message:

There is no assurance this key belongs to the named user
[stdin]: encryption failed: Unusable public key

I already set the the trust of my key to ultimate als suggested here

And also checked that my key is not expired. Any suggestions how to fix this or should i get a new key?

From https://stackoverflow.com/questions/33361068/gnupg-there-is-no-assurance-this-key-belongs-to-the-named-user:

do gpg --edit-key <KEY_ID> and gpg>trust

If you're sure about the authenticity of your key, select the trust level 5.

Solved the problem by running:pass init <gpg-id> which reencrypted the existing keys. Afterwards i was able to decrypt my keys again normaly