Originally Posted by
UAPremExecflyer
Don't assume anything ... most of the time you receive your second (and maybe third) BPs at the departure point ... but sometimes technology or security (SSSS or similar) prevents it ... if you don't receive your UA BP in PRG, then you can easily pick up one at an LH transfer desk when arriving in FRA ... and then go to the gate ...
and the UA gate might make you get another BP from them in the morning. I was even told once by the UA staff (contractors) that I had to get a physical BP instead of my mobile BP at FRA. The good news is that, as
UAPremExecflyer noted, you will usually get a BP in PRG that will be enough to get you through security in the AM at FRA (I'm assuming that you will be staying at a hotel for the long layover).