Error - Unable to write DKIM settings - no or invalid DKIM-Path defined

I created a DKIM KEY for a domain located on a SLAVE server.
My monitor for my master server goes RED.
On the Master server the error "Unable to write DKIM settings - no or invalid DKIM-Path defined" appears in the system log.
I don't understand what creating a DKIM signature on a slave server would have to do with the Master server.

 

The keys are stored on the server that serves the maildomain. Is your slave a mirror?

 

Nope the slave is not a mirror yet.

 

This error occurs if you did not define a path for dkim-keys. If you add a domain on server x, you will not see such an error for server y. The plugin is called if you change / create a maildomain.
If you see the error on your master-server, you must have maildomains with dkim on you master.