When upgrading a Mikrotik LHG5 the new software lowers the tx power not allowing it to connect it puts it on outdoor mode and will not connect to a access point only way to get it to connect is to turn the Installation mode to Any instead of outdoor.
I think getting rid of the antenna gain function is the problem, doing the above makes it work but if your are upgrading a remote location do not upgrade your router OS or it will go away and you will have to go there and change the Installation to ANY until they have a fix for this
I learned the hard way upgrading 4 units at the same time before realizing they did not come back and had to run out to the customers house to get them back up.