I just upgraded my turret to the final level of M0, but now I can't get the M1 for free. What should I do?
I understand your situation. The thing is, you will get the M1 modification's visuals for free ONLY after you reach the required rank. But, until then, you can play with that M0 having the same stats of stock m1 without the visual appearance of the M1.
Let's say you have smoky m0 and you fully micro upgrated it to m1 you need to reach the rank required to unlock the m1 modification so that you can get it but be careful, if you reached the rank where you unlock it's m2 or m3 then you won't be able to get it's m1. You will only be able to purchase its highest modification which is available for your rank.
Customer support service by UserEcho