Unable to create a new electronic signature in Preview

Solution 1:

Perhaps the storage of signatures is corrupted.

Try quitting Preview and deleting the ‘Signature Annotation Privacy’ entries in Keychain Access if you don't mind losing the one you already have.

Previously, the signatures were stored in Preview's container. You can try printing or deleting the store using read or delete in

defaults read ~/Library/Containers/com.apple.Preview/Data/Library/Preferences/com.apple.Preview.signatures

Solution 2:

So, on Big Sur 11.6 and Preview 11.0

If you click on the sign button then you get the X to delete the signature which you can then replace.

Now it seems to let me create several having created and replaced one…