Time Capsule: "There was a problem connecting to the server" I have a dream:  The dream of using my MBP inside and outside my office, and having it backup to my 2TB Time Capsule when on its wireless network, or postpone backups when not on the Time Capsule's wireless network.

Unfortunately, if I've been on a different wireless network for a few hours worth of backup attempts, bringing the machine back onto the Time Capsule's wireless network doesn't clear up the problem.  I can select the disk as a backup drive in the Time Machine preferences, but the disk remains unavailable from the Finder, and any backup attempts yield the standard:


  There was a problem connecting to the 
  server "Max Time Capsule"
  
  Check the server name or IP address, and then try 
  again.  If you continue to have problems, contact your 
  system administrator.


My WiFi connection is through the same Time Capsule that hosts the backup drive, and its name and IP address have decidedly not changed.  The only thing that seems to help is restarting the Time Capsule, but that is an inconvenient workaround at best.

The problem sounds similar to Backup Disk Not Available, but the answers to that question are either to restart or change the disk name or turn off the 5 GHz network (which didn't help).  I also looked at /Library/Preferences/com.apple.TimeCapsule.plist, but found nothing that seemed relevant.

Any suggestions would be greatly appreciated.  My MBP is running OS X 10.7.5, and the Time Capsule firmware is 7.6.1.
I experience issues like this from time to time. Although running a later version of MacOS (10.13), most of the steps should be similar. 

What I normally do is:


Use AirPort Utility to check if the firmware on the AirPort device is
current, then restart (even if the firmware is up-to-date. 
Run Disk Utility on the Time Capsule backup volume (whether external
or integrated in Time Machine) 
Restart the main computer, holding
down the CMD + R keys to start up in recovery mode, then run Disk
Utility on all storage volumes that are backed up with Time
Machine. 
Disconnect the Time Capsule volume, then reconnect. Hold
down the Option key, then under Time Machine in the menu bar, run
Verify Backups.


Situations like this can be frustrating, and it may take some time to do this, but I find it usually helps. For some other tips, Apple has some suggestions here.