with mods Angel's Petrochem & Bob's logistics, RF3 Tech is Unresearchable
because "plastic" tech is changed to "plastic-1" and "plastic" tech is Disabled.
but RF3 Tech pre-requirement tech has "plastic" disabled by angel's petorchem

I believe you must have more mods than what you have listed to cause this issue, because running the minimalist set of Angel's PetroChem v0.9.17, Angel's Refining v0.11.9 (required for Petrochem), Bobs Logistics v1.1.3, Bobs Functions v.1.13 (required for Logistics), and Reverse Factory v8.0.2, and I see both Plastics and Plastic 1 in the tech tree. RF3 prereqs are Advanced Material Processing 2 and RF2, as intended.

I think you might have Bobs Intermediates (which is not actually a requirement for either mod)... but running that same set with Intermediates mod still doesn't cause the issue you have described. With Bobs Intermediates, I see RF3 prereqs as Plastics and RF2, and Plastics is still researchable. Trying different combinations of Angels/Bobs and still not seeing this issue.

More information required

i have the same problem. but instead of playing angels and bobs mods solo, i play with the seablock mod. basicaly it used angels and bobs mods.
so i removed the prerequesite "plastic" but nothing changes. the RF3 ist stil unlockable.

Hm.... okay, I tried installing the minimalist set of Seablock v0.5.4 (which includes Bobs Functions v1.1.4, Bobs Electronics, Logistics, and MCI v1.1.3, Angel's Bio Processing 0.7.17, Petrochem v0.9.17, Refining v0.11.19, and Smelting 0.6.14): Plastics tech was removed, but RF3 was still researchable, requiring only Oil Processing and RF3.

I tried adding a few more bobs mods, but still couldn't get the issue to appear. It could be something that only appears with a certain load order? I'll try to tweak the logic to see if it fixes anything, since I can see where it might break.

Alright, I've uploaded an attempt at fixing the missing Plastics tech issue. Instead of only checking for the existence of the Plastic Pipe item, it also checks for the existence of the Plastic-1 tech, and uses that as a prereq if detected. Otherwise, it will default back to using the Plastics tech as a prereq.

This should hopefully fix the issues with unresearchable Reverse Factory t3? Attempted fix v8.0.4

Problem Solved! Thanks :D

Thanks from me to. i can start the research