After a ConfigMgr 2007 migration where many software packages are migrated, deployment is not working anymore. Every software package deployed gives the same error message in execmgr.log on the client: No accessible source location found for the content. No content is downloaded in ccmcache at all. Still content is available on multiple distribution points.
When looking in deployment properties of software packages, distribution point settings are wrong: Run program from distribution point. Within ConfigMgr 2007 every package can be installed from a distribution point directly. Within ConfigMgr 2012 this is possible only when using Package share settings. When doing this content will be twice on the server, which is not recommended.
Better is to change the distribution point setting to: Download content from distribution point and run locally. That way it will be installed fine after all. Problem solved :-)