First Crash Report:

The mod Belt Balancer (2.1.2) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event belt-balancer::on_nth_tick(8)
LuaTransportLine API call when LuaTransportLine was invalid.
stack traceback:
belt-balancer/objects/balancer.lua:198: in function 'run'
belt-balancer/helper/message-handler.lua:33: in function <belt-balancer/helper/message-handler.lua:31>
stack traceback:
[C]: in function 'len'
__belt-balancer/objects/balancer.lua:198: in function 'run'
belt-balancer/helper/message-handler.lua:33: in function <belt-balancer/helper/message-handler.lua:31>

Second Crash Report:

The mod Construction Drones (0.4.11) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event Construction_Drones::on_ai_command_completed (ID 113)
The mod Belt Balancer (2.1.2) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event belt-balancer::script_raised_built (ID 77)
LuaEntity API call when LuaEntity was invalid.
stack traceback:
belt-balancer/objects/balancer.lua:140: in function 'recalculate_nth_tick'
belt-balancer/objects/belt.lua:225: in function 'built_belt'
belt-balancer/control.lua:102: in function <belt-balancer/control.lua:87>
stack traceback:
[C]: in function 'index'
__belt-balancer/objects/balancer.lua:140: in function 'recalculate_nth_tick'
belt-balancer/objects/belt.lua:225: in function 'built_belt'
belt-balancer/control.lua:102: in function <belt-balancer/control.lua:87>
stack traceback:
Construction_Drones/script/construction_drone.lua:1915: in function <Construction_Drones/script/construction_drone.lua:1887>
(...tail calls...)
core/lualib/event_handler.lua:44: in function <core/lualib/event_handler.lua:42>
stack traceback:
[C]: in function 'create_entity'
Construction_Drones/script/construction_drone.lua:1915: in function <Construction_Drones/script/construction_drone.lua:1887>
(...tail calls...)
core/lualib/event_handler.lua:44: in function <core/lualib/event_handler.lua:42>

I can replicate the bug when using the Belt Balancer (Mod) and an upgrade planner to change yellow belts to red belts on belts touching belt balancers

The belt balancer mod is at fault here, please report it to the mod author

I have fixed this in the belt-balancer with release 2.1.3 for factorio 0.18.

In theory also fixed for factorio 0.17 with release 1.2.3, but Construction Drones does not call script_raised_revive in 0.17 releases, so my mod has no idea, that the fast-replacement happened :(