So I had a drive fail.  I stopped the array.  Removed drive and replaced it.  When I assign the new drive to array and go to start array there is this error:

 

Stopped. Invalid expansion.You may not add new disk(s) and also remove existing disk(s).

 

What should I do?

Please post your diagnostics: Tools -> Diagnostics

Here it is.

milyard-tower-diagnostics-20181126-1337.zip

Something missing in your account, I see no failed disks, I see an array with both parity disks invalid and no disks 3 and 9 assigned, Unraid started a parity sync on both parities and you canceled an tried to add a new disk to slot 9, the error you're getting is misleading and an old reported bug, but you can't add a new disk before both parity disks finish syncing.

1 minute ago, johnnie.black said:

Something missing in your account, I see no failed disks, I see an array with both parity disks invalid and no disks 3 and 9 assigned, Unraid started a parity sync on both parities and you canceled an tried to add a new disk to slot 9, the error you're getting is misleading and an old reported bug, but you can't add a new disk before both parity disks finish syncing.

Even when I cancel the sync I can't add drives.  I had to replace 3 and 9 but trying to just do one at a time right now.

Oh, and if there should be a disk3 and/or disk9 that failed before current logs, then you did something wrong, like doing a new config.

Just now, rmilyard said:

Even when I cancel the sync I can't add drives.

 

3 minutes ago, johnnie.black said:

you can't add a new disk before both parity disks finish syncing.

 

or if you really want to add two new empty disks, unassign both parity disks, start the array, stop the array, assign both data disks, stop the array, re-assign both parities to start syncing, and in case it's not obvious both new disks won't have any data, they will be empty.