I noticed that in the newest 0.17 version, the UI for your inventory covers the UI to buy items. Since you can't move UIs anymore, this make sit impossible to buy most items. Thank you for reporting. Could you attach a screenshot of the issue? Also do you use the latest experimental version of Fact...

can you unlock the buy window some mods that have windows locked to the left side push the black market window down and cant access the items on the buy lists i think it was unlocked in factorio v14 or 15