Problems signing in with Apple ID

You are trying to sign in to Wikiloc with your Apple ID and you get an error saying "An error occurred while trying to sign in with your Apple ID"?

This may have happened because your Apple ID has already been paired to Wikiloc before, or for some reason, it could not be paired correctly.

To fix it, unpair Wikiloc from your Apple ID:

Go to your Apple account manager (https://appleid.apple.com) and sign in with your Apple ID.
Security > Apps & Websites using Apple ID > Manage > Wikiloc Outdoor Navigation GPS > Stop Using Apple ID > Stop Using Apple ID
You can try to sign in with your Apple ID to Wikiloc again.