Case: the client installed the android dogecoin wallet (Langerhans dogecoin wallet) on his phone a couple years ago. he moved all his dogecoin to the wallet and forgot about it as the price of dogecoin was really low. however, as the price increases so much and he remember the wallet backup in his email and get restored the wallet successfully. but he found there is a unknown Spending Pin set on the wallet he could not remember. he also tried to decrypt the wallet backup but failed.
Solution: users can’t decrypt the backup without removing the PIN. we brute forced the spending PIN. then removed the 8 digits PIN. decrypted the backup. imported to core wallet and move coins to his Binance account.