Airport Time Capsule not connecting

The Airport Utility connecting window says "An unexpected error occurred. Try Again."

Make sure that IPv6 is set to link-local only as per point 4 in the instruction set.

If you keep getting a failed setup then plug in by ethernet in full isolation to the network and do the setup manually.

See Airport Utility shows "unexpected error - please try again" when connecting to Time Capsule

I have written it up multiple times because it does really help when you get stuck in that loop.

If you need more help then post screenshot of where it is messing up.

Are you using Time Machine for backups?

I have not seen DiskImageMounter error before but anything is possible (in Sierra).

To get access into the Time Capsule again reset it. None of your files will be lost.

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.

Setup the TC again.

Then redo the setup from the computer you want to use for TM using Airport Utility.

1. Use very short names.. NOT APPLE RECOMMENDED names. No spaces and pure alphanumerics.

eg TCgen5 for basestation and TCwifi wireless name.

If the wireless is still a problem set wireless names like TC24ghz and set the 5ghz to different name.. eg.TC5ghz

2. Use all passwords that also comply with 1. but can be a bit longer. ie 8-20 characters mixed case and numbers.. no non-alphanumerics.

**3. If the TC is main router you can skip this point. This is only an issue when the TC is bridged.

Ensure the TC always takes the same IP address.. you will need to do this on the main router using dhcp reservation.. or a bit more complex setup using static IP in the TC.

Ignore this point if you don't understand it .. post back if you have drop out issues.

4. Make sure IPv6 is set correctly in the computer. ie link-local only for ethernet and/or wireless depending on which you use. Auto is not good enough.

For reliable backup I strongly recommend using Carbon Copy Cloner or one of the alternatives (superduper, Chronosync). TM has major issues. But there are still network issues with Sierra so local backups are the other alternative.

You could try to backup via Ethernet. After much searching (& not finding how) I have discovered how to back up via Ethernet in airport utility 6.3.6.

Connect a Ethernet cable between your computer and a LAN portof your time capsule. Then connect a Ethernet cord from the LAN port of your modem to the WAN port of your time capsole. The WAN port is a circle made of dots. Set up your time capsule giving it a name, password & what not. When you get to the wireless section of the settings for the time capsole turn it to off. On the main screen of airport utilities you see a big icon labeled internet and then a line going down connected to your time machine. In the upper left corner of that screen is a rounded button labeled 'other wifi devices'. When you click it you can select either Ethernet or wifi, meaning you can select to connect to the time capsule over Ethernet or wifi. Select Ethernet & then go over to your network preferences. Turn wifi off. Go to time machine preferences. Ensure that you have the correct name for your time capsule & start your back up!