I am sorry, I have misunderstood how far you have been getting.
I also get the Internal Error: Missing Template MGR_INDEX when I select Cache Manager Interface from the menu.
This menu is coming from squid and I believe the Cache Manager Interface requires some other program from squid that is not installed from IPFire.
The table you show from @mustangint1 should then be seen if you select the menu item Service Times (percentiles). Do you see that table. If not what do you see?
Yes…the table can be viewed.
However, I was understanding that clicking the [Cache Manager Interface] should display a “cache” view of any/all url links visited via the proxy or network? Was/Is this correct?
On another note, please advise what search tool is being used in ipf? mlocate seems to have been removed.