first some general remark, BUG report below ...

I couldn't resist continueing to use this mod although the start is still quite hard for me since i am using it as part of a modpack with several other "space themed" mods which change/add on the research tree, delaying eg bots for quite a while. i just apparently got almost stuck with two other mods: one protects bots by additional research/tasks which requires more work and time, and thus this mod requires lots of manual repairs and replacements (the repair chest and the recycler are a blessing) taking up most of the work and time i have. those replacements rarely happen on most of the normal machines but frequently on a larger setup of labs: half the science labs are waiting for replacements all the time and most of the other labs need repairs, many even with items that i can't make yet (i need armor first to kill biters at the oil, which in turn needs the oil first, and in between also those locked researches).

nonetheless, i somehow enjoyed the challenge until i just got the following crash when i hit "M" to show the map. because the crash happened again when loading the last autosave, and no longer happened after using the previous autosave from before that, it is probably also related to some other mod which had added a special "science bot" between those two autosaves. but the error only shows this mod's name :

The mod Maintenance Madness caused a non-recoverable error.
Please report this error to the mod author.

Error while running event MaintenanceMadness::on_tick (ID 0)
LuaEntity API call when LuaEntity was invalid.
stack traceback:
MaintenanceMadness/control.lua:922: in function 'processMaintenanceUnit'
MaintenanceMadness/control.lua:1682: in function <MaintenanceMadness/control.lua:1574>
stack traceback:
[C]: in function 'index'
__MaintenanceMadness/control.lua:922: in function 'processMaintenanceUnit'
MaintenanceMadness/control.lua:1682: in function <MaintenanceMadness/control.lua:1574>

just for info: although that old map is still running on my computer and thus i disn't update anything, i didn't get the above error again ... using that previous autosave and avoiding to get that science bot, i continued playing without problems. and a while later after building a special "roboport" that belonged to that other mod, i dared getting that science bot again and opened the map without problems.
no idea whether the crash was related to that other mod, whether it was a problem of having that bot without that special port, or something else in that mod or in this mod.

Meh, it's my fault. I just forgot to add the check if the connected energy interface is still valid. It seems that one of your mods has somehow removed it. This issue should be fixed now. If the energy interface entity gets lost, it's simply recreated.
Also, i found a potential issue with invalid maintenance units not being removed from the maintenance units list, which is also fixed now. Thank you for your report! :)