See this Comm Center thread involving Andre Ioda. Plan.wsc in the installer is old, and it may be installed even on a system that has ACP on it, which would be bad since it might override a newer one belonging to ACP. In any case, the Plan.wsc should be updated to the one for ACP 7.
Also, XML_RTML23.dll appears to be installed into the ACP application if ACP is installed. This is clearly a mistake. I think my idea was to update the one in ACP or to put it into the Planner install folder if no ACP is installed.That part of the installer has some weird flags (not vital, permanent) also. But it should not do this if the one with ACP is newer!
This stuff should be done in a custom action if needed.