Hi there! I understand you're seeing an error when trying to log in to the JPay app on your Macintosh running OS X 10.15.7. To help you better, could you tell me if the error message specifies anything else? For example, does it mention incorrect credentials, connectivity, or maintenance?

Meanwhile, let's try a few steps to fix the login error:

1. Log out of your account if you are partially logged in
2. Clear your browser cache and cookies: On OS X with Safari or another browser, this helps remove stored corrupted files that might block login.
3. Make sure your internet connection is stable and working properly.
4. Try logging in again after these steps.

If you are using the JPay app on your Mac as a web app or in a browser, clearing cache is especially important. If this does not solve the problem and you still get an error, please let me know what the exact error says.

Also, it could help to try logging in from a different browser, like Chrome or Firefox, if you have those installed.

If these basic steps don't fix it, we can look deeper into app settings or account-related issues.

Are you comfortable trying these steps now? Let me know how it goes!