"Backup Disk Not Available", Time Machine can't find Time Capsule any more I have a 2 TB Time Capsule and it was used by Time Machine for many months.

Some days ago the Time Capsule was disconnected from its power supply and today is now connected again. 

Time Machine reports the error "Backup Disk Not Available".

The Time Capsule lights are green, AirPort Utility is showing this device with green lights also. 

Time Machine knows how much space is available on that device. However, it is not able to use this device for listing older backups or to create a new one.

I can't see this device in Finder, although I couldn't see it there when everything works fine. Airport Utility reports an IP Address for this device and I can ping it. 

What to do now? Is it possible at least to mount it to access the files on it?
I had a similar effect a few days ago. 
I was able to select the disk (see your last printscreen) again and from then on it worked flawlessly... Can you select your disk again?