^^
https://imgur.com/a/Eob2BDL

if there's no way to fix this since some mods require no alone tech to be unlocked but some ex enriched fuel unlocks when uranium proccessing is unlocked etc you aren't detecting the technology part right or you arent' able to detect it at all, if that's so i highly suggest to change the "payment" method to only items based on vanilla and not requesting items created by other mods...

another idea is to put a blue requester chest which requests x items and once items are load into the chest the area unlocks and chest disappears meaning payment collected.

Having a requester chest could be somewhat nice for mid/late game as you can use robots to automatically provide items to these chests and terrain unlocks automatically!

I'd rather add a remote command for people to add items do blacklist
I cant control here everyone's modded items without a prior technology requirement, and I don't like the idea of using vanilla items only.
from what mod is that unknown item ?

that's from https://mods.factorio.com/mod/op_train_speed adds new type of fuel called "Enriched Rocket Fuel"

See that uranium enriched item should be locked behind uranium fuel processing tech. There is no sense for it to be enabled before that tech.
Ask the mod author for a fix. I will add a remote here for a blacklist, on next version.

there are many mods same as this op_train_speed that unlock stuff and don't require technology tree to be unlocked

i don't think coming around and asking all these ppl to change their stuff, i also think blacklist is not a good idea for 2 reasons
1. ppl can blacklist everything and let like only wood ez to made.
2. how will it work? what happens if you add a mod after you've create the map? it should have a in game menu to change blacklisted items at anytime or if blacklist is possible to create only once at the begin ppl could have problems if they add mods after they create map..

Ok, blacklist is the solution then. I will not control this item by item on hard code each time an item like this show up. I dont care if people want to ruin its own game blacklisting everything

1. how will it work? what happens if you add a mod after you've create the map?
   prices are picked once someone click the coin button. So if you a add a new mod, all new clicking may show the new items

Hi I have a similar problem with Factorissimo 2. The Factory buildings it adds are stored in the players inventory as Factory Building Mk1 (Inactive) but the building needed to unlock the land is just the Factory Building Mk1.
This is with mod version 0.18.31, game version 1.0.0, Factorissimo2 version 2.4.3.