Code 900 is "Same kind of license key is activated" according to the license error guide. This could be a few different things, when you updated your server, did you do an update patch, or a new install? If you did a new install, and didn't de-install PostgreSQL, you may still have the old license on the DB. I found this one out the hard way. If you did a server update patch, you may simply need to shut down the services related to Magicinfo, and restart them. Check your license in localhost, as well as your actual server address. Make sure they are both showing the same thing, otherwise you may have continuing issues.