Alright, it is a known issue with SML. We need to wait or use experimental mode. From the discord:
" SML 3.1.0 just released, and it fixes that crash, alongside some other fixes and changes.
This version of SML is only compatible with the build 151773 (and up) of the game, this means that it is currently only compatible with the Experimental branch of the game. Because of this, we suggest you switch to using that branch while waiting for it to merge back into the Early Access branch.
Some mods may have become broken because of the SML update. We already know about Micro Manage and Smart. The fix is simple and those mods will likely be updated again. But as always, please do not ask for ETAs. Mod updates will come when they come.
Please remember that all of the mods are made by volunteers who do this in their spare time ! Happy modding everyone!"