What software version are you at? There won't be any more upgrades with the discontinuation of Legacy.
I've been running 1.4 in my 990 since it was released. My 993 came with 1.6 and it works just fine with the 1.4 base.
I bought a pre programmed 1.6 base module from Charles Ro because upgrading isn't feasible with my 20 year old desktop computer.