Shipping Failed: not reciprocally linked with pin 'ReturnValue' on node 'Get Data Table Row NONE'

I have several error like the one shown below.
On 4.15.2 everything was fine (I guess) or they appeared after I tried to mess around with nativisation - which now is disabled.
I tried to move to 4.16 but it didn’t help.
I tried to fix them somehow but in the end I broke entire project (it started to crash on start-up).
Almost all are related to data tables with “None” data table - which I checked, I don’t have any.

Log:
link text

I’ve started getting the error as well since upgrading my project from 4.15.3 to 4.16.1.

Maybe it’s related, or maybe I broke something else and just now discovered it.

The editor crashes and gives a bunch of the following errors if I try to make a build, or if I try to open a map that does not have my main character placed in it without first having already opened a map which does have my main character placed in it.

UATHelper: Packaging (Windows (64-bit)): Cook: LogOutputDevice:Error: Ensure condition failed: ToPin->LinkedTo.Contains(this) [File:D:\Build++UE4+Release-4.16+Compile\Sync\Engine\Source\Runtime\Engine\Private\EdGraph\EdGraphPin.cpp] [Line: 333]
UATHelper: Packaging (Windows (64-bit)): Cook: LogOutputDevice:Error: UEdGraphPin::BreakLinkTo Pin ‘then’ on node ‘Assign’ not reciprocally linked with pin ‘RowName’ on node ‘Get Data Table Row NONE’

Right now I don’t get those errors any more, but I don’t know if they are entirely gone, because I’ve got this error first: EXCEPTION_ACCESS_VIOLATION reading address 0xffffffff - Platform & Builds - Unreal Engine Forums

I’ve got them back, they appear at random - like when I fix something they appear in different order, or new ones.