For a while now, LP has been expiring passwords every 6 months. You want to make a note to get on the system and change it yourself at least every 6 months.
If the system went belly-up (blank page) when you asked for a new password, that sounds like there's a bug in the system. It should be reported to email@example.com. While you're at it you can ask them to supply you with a new password, or wait until they fix the lost password system. Be sure to check your junk/spam/bulk email folder first, as the email may have ended up there. Also, have you changed your email address? Responses from support (and the new password) will go to whatever email address is on file. If you no longer have that one, you may be requested to provide some proof that you're the owner before they will send to a new address.