P.S. this was ran with Bob's mods

i get same error.
and im only using Black market (Sell and Buy) and the scenario for it.

It looks as though "electric-energy-accumulators-1" was the name of the Electric energy accumulators research. It appears as though it was recently changed to "electric-energy-accumulators". For those interested, you can fix this mod manually.

The erroneous file within the mod zip file is "prototypes\entities.lua". In any text editor, you can search for the text "electric-energy-accumulators-1" and replace the one instance with "electric-energy-accumulators". I haven't tested the mod beyond opening a new world, but the menu and research are present, so I assume it's running fine.

Here's hoping Totobest will update this officially. :)

That fixed it. Thank you DrFreenote.

The issues still occurs in 17.40 and higher

@Alco It's not going to fix itself, the name of the technology changed in Factorio 0.17 (which you can tell by comparing data.raw from 0.16 to that of 0.17). It isn't a bug on Factorio's end (hence why it won't fix itself), it's just outdated code in the mod. If you want to use the mod again, you'll have to fix it yourself, because it's very apparent (both by their own admittance and by the time since the last update) that the mod maintainers are not going to do it for you. They're done. But on the bright side, once you fix it, you're golden. It'll never get wiped because they aren't updating it. Someone could take over the mod, but it would seem no one is interested.

Is fixed by following @DrFreenote's instructions. Thank you kindly.

can we get an update so this works multiplayer?

I've forked the mod, and will do my best to maintain it.
https://mods.factorio.com/mod/BlackMarket2
https://github.com/djmango/BlackMarket2

Thanks, this is a great mod...