I spawned a vehicle and I get a spam of errors with this:

[Gredwitch's Base] lua/gredwitch/gred_cl_simfphys_functions.lua:215: Tried to use a NULL entity!
1. GetNWInt - [C]:-1
2. v - lua/gredwitch/gred_cl_simfphys_functions.lua:215
3. unknown - lua/includes/modules/hook.lua:96

[Gredwitch's Base] lua/gredwitch/gred_sv_simfphys_functions.lua:506: Tried to use a NULL entity!
1. GetNWInt - [C]:-1
2. v - lua/gredwitch/gred_sv_simfphys_functions.lua:506
3. unknown - lua/includes/modules/hook.lua:96

But whenever I get on that vehicle, the errors stop appearing.
Any clues on what's the issue? Has anyone also experienced this, and if yes - is there a fix?
(And yes, this happens on any Gredwitch vehicle I spawn, including from Shelby tank addons.)