Using El Capitan 10.11.6, getting Keychain error code 1000001while connecting to Time Capsule for a data backup. Works fine on Macbook that doesn't use keychain.
Can I disable keychain?
iMac with Retina 5K display, El Capitan 10.11.6
Please read this post: Re: Re: Re: Airport Time Capsule - Setting Up - Impossible
It's quite long and describes an unusual Time Capsule installation, so scroll to the bottom and read the very last post by the OP. It references an earlier Discussion. That may be the fix you need.