Is 3 minutes per turn within acceptable limits? It seems to be very long compared to the playthroughs I've seen on YouTube. I've tried it on two computers - one with Intel i5 and other Intel i7 processors and the difference after 30-40 years if gameplay is not great. I've yet to inspect this more thoroughly but due to monitor problems, the i7 is currently being repaired. Also, on both computers 5 day turns taking about the same time as 30 day ones.
About the overflow bug, when assigning new ship to be constructed I'm getting Error in PopulateShipyardTasks, error number 6, overflow. The same one appeared before with errors in minerals and in production but have not happened again. After clicking "ok" several times the error disappears and the ships are being built.
Also, my system is set to use , as grouping symbol and . for decimal symbol. Never experience any error before.