You are probably running out of the people u need to run the corps. Try using your coins to buy a population transfer or 2 for your country. Also make sure u set the salaries of your corps to start at around 200. youll want to go higher eventually, most ppl say 700-800 is best. Dont build more untill u get your population boosters.
dont buy more than 2-3 mill population transfer at a time cause all those unemployed people will cost u money.