This only applies if you are a joiner NOT the host.
Yesterday I was kicked out with an "error1a", no complaints, these things happen. I tried to rejoin from the option on the Error Screen, it allowed me to rejoin but I had a square cursor and could not give order to Corp etc.. If this happens to you, try this:
I quit from the game, shut down HWLG completely, relaunched and rejoined the battle, this time with no problems and all my orders were still preserved.
P.S. The Host G24 paused the battle while I did this, so that I couldn't be attacked etc... whilst rejoining