1.6.2 Unable to remove all assigned files from Display Group

Assigned files? Could you give exact steps to reproduce please

Log into the Xibo server through a browser.(In my case I am using Ubuntu 14.04 and Google Chrome.)

Click on Displays and then Display Groups.

Click on the Action button next to a Display Group(In my case I am choosing one that was already in existence before upgrading and one that already had files assigned to it.), and click Assign Files.

Click the "-" minus sign next to each assigned file until they are all gone, and then click the assign button at the bottom.

The error I am getting should appear below the buttons.

Assigned files is there for future ability to upgrade client installations
from the CMS where you would want to remove the currently assigned
installation. That's probably why it's preventing you removing it as it's
the currently assigned image for one or more clients

Assuming you haven't set an assigned file as the upgrade target (as Alex suggested) then this sounds like a bug. I'll create a bug anyway as a more appropriate error message would be useful.

"Assigned files is there for future ability to upgrade client installations
from the CMS where you would want to remove the currently assigned
installation. That's probably why it's preventing you removing it as it's
the currently assigned image for one or more clients"

Alex,
Sorry for my ignorance here, but I am not sure I am following what you are tell me. Are you telling me that assigning files to a display group, as of right now, actually does nothing? So the ability to remove all assigned files does not really matter anyway? And are you also telling me that one of the displays in the display group is using the file I am trying to remove, so it is not allowing it to be removed?

Thanks Alex Harrington, that solved my question.