When opening a master project from Clarity to Microsoft Project (MSP), a popup window opens looking for the file in the MSP Bin folder. Example of the file path that launches in the window:
"Program Files (x86) -> CA -> PPM - CA PPM MSP Interface -> Bin".
A message at the top of the window states "Cannot find inserted project - <Project Name>". When you click 'Cancel' to the message it takes you to a mpp file with just the list of the sub projects, but not tasks for the project.
This is due to a problem with one of the sub projects of the master project. One known issue with sub projects that causes this issue with a master project is if either the Standard calendar or a team member's calendar is 51 characters or longer. If this is the cause, you will see the following error when attempting to open that sub project in MSP: "An Import error occurred. The element in the element with = <ID#> has invalid data. The calendar name does not exist. Click a calendar in the list, and then press Enter". Reference MSP Error "An Import error occurred..." / unable to open project a calendar has more than 51 characters for more information on this issue.