same thing happened to me, but here's an explanation from Matthew in the other forum, hope it's alright to post it here
Hi everyone
There was a strange flurry of activity on the e-CAS Tracker this morning, far far more than usual, so I took a closer look at what was going on.
It looks like CIC has removed the address info from a huge number of people's e-CAS files. Of the 389 files currently being tracked where e-CAS is already working, more than 1 in 7 had their address info removed. There's no reason to think this would be limited to those using the tracker.
I have no idea why this is. The only time I've known this sort of change to occur has been the other way round, when someone sends in an address change, and then later it appears on e-CAS. I've never noticed addresses disappearing like this, certainly not on this scale.
Whether or not you use the tracker, I'd suggest taking a look at your e-CAS, and if it used to show your address but doesn't any more, you may want to phone the CIC call centre to find out why, and make sure they still have your correct address info on file.
Matthew