Same issue at linux server and my windows client save.
Error while running event kry-logistics-reactor-next::reactor-requester-on_initialized (ID 344)
kry-logistics-reactor-next/scripts/reactor-storage.lua:61: attempt to concatenate global 'localised_name' (a nil value)
stack traceback:
kry-logistics-reactor-next/scripts/reactor-storage.lua:61: in function 'set_reactor_requests'
kry-logistics-reactor-next/scripts/reactor-storage.lua:173: in function <kry-logistics-reactor-next/scripts/reactor-storage.lua:143>
stack traceback:
[C]: in function 'raise_event'
0-things/control/events/downstream.lua:32: in function '?'
0-things/lib/core/event.lua:198: in function 'raise'
0-things/control/thing.lua:645: in function 'initialize'
0-things/control/automatic-children.lua:90: in function 'create_child_thing'
0-things/control/automatic-children.lua:149: in function 'check_children'
0-things/control/automatic-children.lua:226: in function '?'
0-things/lib/core/event.lua:198: in function 'raise'
0-things/control/frame.lua:459: in function 'terminate'
0-things/control/frame.lua:175: in function 'on_subtick'
0-things/control/frame.lua:466: in function 'handler'
0-things/lib/core/event.lua:299: in function '?'
0-things/lib/core/event.lua:109: in function <0-things/lib/core/event.lua:107>"

Interesting, I hadn't tested with multiplayer at all, but I thought it would still work there if it worked in single player, I'll have to look into this, maybe have to use the same fix I mentioned in the other discussion thread

Should be fixed in v7.1.1

For some reason, the localization requests don't go through when loading a multiplayer save, so I just removed them entirely and went with a different method for the default reactor request names (further info in the other discussion thread)