Steve on 23 Nov, 2022 08:25 PM
welcome to the GPGTools support platform. Sorry to hear you are having problems using GPG Suite.
The error message Invalid digest algorithm along the note Third-party key signatures using the SHA1 algorithm are rejected indicates, that the algorithm preferences for your key are outdated or your key is too old to support better algorithms.
To check your algorithm preferences you need to enable expert settings. Then select the key and in the menubar Key > Algorithm Preferences…. Make sure to disable the expert settings once you are done.
Feel free to send a screenshot of your algorithm preferences view along with the key details after double-clicking your sec/pub key in GPG Keychain.