- Open the Server Manager.
- While the manager is still open, open up mirth.properties in an editor and save it.
- Go back to the manager, make some change, and hit Apply.
These steps will usually cause mirth.properties to wig out. In particular, the protocol / cipher suite entries will for some reason decouple into multiple lines, causing HTTPS traffic between the client and server to fail.
As a workaround, just make sure to close (do not hit OK or Apply) the server manager and tray icon and reopen it whenever you want to make any changes using it.