Migrating from v 3.5.2 to 5.3

I was told that I can just move over my .dbs file and preference.xml file. This doesn't work. I can't use the .dbs file from my old server as it says it is invalid. I really need to to work asap. Please advise how I can move my jobs over to my new server.

If it's from version 3, the files are incompatible. To upgrade the job database you need to have both versions installed on the same system. The new version on startup will migrate old jobs to the new version format. After that you can copy the new job database file to the new system.

Alternatively you can use Import Jobs from Remote Schedule option, it's in the Tools menu. When you install new version on the new system, in the scheduler settings setup Remote Agent profile pointing to the old system. Use the mentioned menu, choose the profile for the old system and then import all jobs. You may still need to recreate manually job queues and saved database connections to the imported jobs run successfully.