There is a release switch to remove the adapter (red arrow), if you don't use it and pull too hard, it will break, and in our case, it broke the Wifi adapter and the board in the printer. It is't fixable without replacing both.
We have it working(ish) by fiddling with it until it worked, and then just making sure not to touch it ever again (or until it stops working and then we fidget with it again. :-(
My versalink c400 printer and wi-fi adapter were working together without any problems then one day the printer just stopped recognizing that the wi-fi adapter was plugged in. After I initially installed the adapter I didn't even touch the adapter, after days of it not working I tried taking it out and reinstalling it and now it's feels like it's just sitting in the hole and not actually connecting with it's female counterpart. Has anyone else had this problem or know what I need to do to fix it? There's no where in my office to just plug it directly into my router or I would just do that, my router is on the opposite side of the house and on a different floor so it'd be hard to find a cord long enough to reach.
Someone please help me!