If you have patched your live client and it now points to the test server (no dimension selection box), or the other way around, you have - for some reason - gotten the wrong dimension file.
To correct this, download the dimensionserver.url file for the dimension(s) you want to reach, and save it in the \Anarchy Online\cd_image\data\launcher folder of the client installation.
Download DimensionServer.url files here:
To the live dimensions
To the test dimension
If this doesn't work, please contact techsupport@anarchy-online.com.