Hmm that is very strange. What other mods do you have enabled in combination with this one, where the problem occurs? I'd like to see if I could reproduce the issue.

I don't know if this is the same, but I had that problem when I was loading a mod to make the Explorer stronger. When I unloaded that mod the unit command window came back.

This is not a problem exclusive to InfoAddict. This appears to be a game bug related to mods in general; some cause it, some don't. At this point the cause seems to be unknown. It has been reported as a bug on the 2k forums. There are threads talking about it on the CivFantic forums here: http://forums.civfanatics.com/showthread.php?t=537796 and here: http://forums.civfanatics.com/showthread.php?p=13535858 .

I have not personally experienced this with InfoAddict as the cause, but I can confirm that it can occur regardless of whether it is multiple mods being loaded or only one. Based on reports and personal experience the extent of this bug seems to be wider than is currently realized.

My only suggestion on dealing with this problem is to back out to the main menu, turn off the mod that seems to be causing the issue and start a new game. If the unit UI is back, return to the main menu and turn the mod back on, then try again. If the unit UI is not back on, exit to Windows and try again. Doing this I have gotten the game to work with more than 10 mods loaded at once, including InfoAddict.

TL;DR
It's a game bug. Unload the mod, try again, then reload it. Rinse and Repeat.