Whenever I try to open my inventory, I get the following message:
Error while running event FNEI::on_tick (ID 0)
FNEI/controls/options_control.lua:42:
attempt to index field 'settings' (a nil value)

I also get a similar error when I try to open the FNEI interface:
Error while running event FNEI::pressed-fnei-gui key (ID 134)
FNEI/controls/options_control.lua:42:
attempt to index field 'settings' (a nil value)

Yeah, this happens since the latest version.

Thank you for reporting the error, I'll try to close it shortly.

fixed