“Backup Disk Not Available”, Time Machine can't find Time Capsule any more

Open Time Machine preferences and reselect your backup disk. If you erased your backup disk and began having trouble, reselecting it may fix the problem. After reselecting the backup disk and pointing it to the folder this fixed the issue. It took a few minutes for everything to work itself out but the system is backing up again.

I found this solution here: OS X El Capitan: If Time Machine can’t find your backup disk

Do a factory reset of the TC.

No files are lost doing this.

Start from a factory reset. No files are lost on the hard disk doing this.

Factory reset universal

Power off the TC.. ie pull the power cord or power off at the wall.. wait 10sec.. hold in the reset button.. be gentle.. power on again still holding in reset.. and keep holding it in for another 10sec. You may need some help as it is hard to both hold in reset and apply power. It will show success by rapidly blinking the front led. Release the reset.. and wait a couple of min for the TC to reset and come back with factory settings. If the front LED doesn’t blink rapidly you missed it and simply try again. The reset is fairly fragile in these.. press it so you feel it just click and no more.. I have seen people bend the lever or even break it. I use a toothpick as tool.

N.B. None of your files on the hard disk of the TC are deleted.. this simply clears out the router settings of the TC.

Run through the setup again in the airport utility.

I strongly recommend names that are short.. <10 characters, pure alphanumeric and no spaces.

Passwords 8-20 characters pure alphanumeric mixed case and numbers.

This will cause TM to lose its link to the backup.. don't worry.

You should now be able to select the TC for backups.. start the backup.. TM will say it is going to do a new backup but will actually find the old backup and then test it and continue with an incremental as normal.

If you find it fails again in a few days.. there is possibly a network issue.. It is important the computer that is using the TC for backup is linked directly to it.. not via another router. Of course using ethernet is about 1000x more reliable than wireless.. so always use ethernet when possible.

Hello sdrfliozuit76,

Thank you for using the Apple Support Communities!

I understand from your post that you are not able to backup your Mac with Time Machine and receive the error “Backup Disk Not Available”.

To continue troubleshooting this situation, I recommend reading over and working through the following article and its suggested steps.

If you can't back up or restore your Mac using Time Machine - Apple Support

Have a great day!

Hi, I followed the document and could not find anything helpful.

1. Airport utility sees the time capsule
2. on finder I can open the "Data" folder and I can see the files inside it
3. I already successfully performed a first full backup a few days ago
4. when I click "Backup Now" in the Time machine menu on the doc I get the message "Backup Disk Not Available - Try backing up again when xxx is available"
5. I rebooted both my laptop and the Time Capsule and still the same message
6. OS X 10.11.2 (15C50), Time Capsule 5th generation 3T
7. Nothing changed from 3 days ago, as a matter of fact all seems to be connected properly

Thanks

This solved my problem.

Thank you for the quick reply. One more thing I would like to mention before doing a factory reset is that I have two mac book pros connected to the same Time Capsule.

The other one is working perfectly fine and just finished a backup a few minutes ago with no problems. This means that the network connection is all OK.

Is there anything I can reset on the mac side without loosing data?

One more thing I would like to mention before doing a factory reset is that I have two mac book pros connected to the same Time Capsule.

The fact that one Mac is backing up ok and the other fails makes it difficult.

Are both Macs running the same OS?

Are both using wireless to connect? Do both connect to the TC directly?

You cannot really fix the problem without messing up the working Macbook unless you are content to keep one Mac working and one not. Eventually you have to try and change the settings .. the easiest is to reset the TC..

To fix the Mac (if that is the problem) you probably need to clean install the OS.. which is a lot more work.

Mac working is using 10.11.3. Mac not working was using 10.11.2, I updated to 10.11.5 and the problem still persists.

The TC is connected with an ETH to the main router and I would like to keep it this way for a number of reasons. I checked the TC instructions before spending quite some money on it and it is supposed to work this way (which indeed it does on one of the Macs).

I will try to reset the TC and let you know if that fixes it.

Thank you!

Do the setup of the TC from the Mac that does not work.

Post again if you have issues.. sadly el capo is no better than earlier versions for how easily it forgets network configurations. ie it simply loses the TC and cannot find it again.

Thanks, that worked