For more than three weeks, it has been impossible for me to log in with my account on the pet rescue game. I feel like I should try again later. I've even created a new account, so far nothing.
Have you verified your email address on your account?
If not, please log in to your King account on King.com on a computer. Then verify the email address and try to connect again on your mobile.
To verify the email on King.com, open the game on the site and click on the disc/ save icon up to the left. Verify the email in the menu that comes up.
Then try to connect the game again on your phone/ tablet. If it still doesn't connect, try with reinstalling the app as well and see if it connects then.