Hello, number of tries is not limited, the only thing we do on mobile devices we postpone another tries as in case of PIN has been used the entire space for master password is quite small and attacker can expect PIN has been used so brute force may be quite easy. So you can try it as many times you want but on mobile device the wait timeout is going to be extended with each unsuccessful try. You may figure out the backup password on windows as I can see you have tried add windows device into the group, there is no such limit. If it helps I can see that your backup password should be the one you have set as master password on device named HTC melsuhl_htc_asia_india at Mar 22, 2016.