Old Command Block Mods not working in new versions

i found out that the vanilla mods that were created with command blocks in old versions such as 1.9, 1.8 and even 1.10 are not working...sometimes it generates an incomplete machines while in other cases it doesn't even generate anything...it would be really helpful if this could be solved since i want to use vanilla commands in the new version of Minecraft so if there is a way you could do some coding stuff (i don't really know much about that) please do it or if its something that can be solved without updating Minecraft i would appreciate that i was informed...