[ygra]

You'd get the wonderful error »Cannot create more units«. There also was a limit with certain sprites that counted towards that. It was not an uncommon error to see in certain UMS maps that had way too many units running around.

[plorkyeran]

You'd also occasionally hit it in zerg-heavy 8 player melee games due to that larvae and overlord count against the limit without consuming any supply. It was always pretty hilarious to see a small pack of mutalisks kill a carrier doom-fleet which couldn't launch any interceptors due to the unit limit.