An application installation might sometimes need the installation media of the previous version, in order to update it. If the installation media is already removed from ccmcache, the installation might fail.
- MECM client can use MECM distribution point as an alternative package source if the installation media was already removed from original source (ccmcache).
- MECM source management doesn't work if communication between distribution point and the client is secured. Make sure your distribution points communication is set to HTTP with "Allow clients to connect anonymously" selected