Looks like I’m in a similar situation having updated my Android wallet to 2.5.1 this evening. Logged into it and zero balance!
I’ve subsequently installed 2.5.1 on my Mac also and have been generating addresses like crazy for the last hour (up to 12 now) with no hint of my balance coming back.
Really confused as to what has happened, and also very concerned that I’ve lost my balance permanently. Anyone know what’s going on?