Property LoginSecure cannot be changed or read after a connection string has been set.

I was stumped on the above error when configuring distributor afresh using SSMS. Eventually found that this is due to impersonate settings that were not setup, so to resolve this simply: Right click local publicaiton-&gt;Distributor properties Select the publisher in the list, click ... In agent connection mode, select "impersonate the agent process account"...(<a href="http://sqlserver-qa.net/blogs/replication/archive/2007/08/24/1713.aspx">read more</a>)<img src="http://sqlserver-qa.net/aggbug.aspx?PostID=1713" width="1" height="1">