General Info

• I didn't add any mods
• I can reproduce this issue consistently in single-player
• I can reproduce this issue consistently in multi-player
• I have searched for this issue previously and it was either (1) not previously reported, or (2) previously fixed and I am having the same problem.
• I am crashing and can provide my crash report(s)
• I am using the latest version of the modpack

Your launcher

Curseforge

Modpack version (Do not say latest check curseforge has it on modpacks icon)

1.7b

Describe your issue

While I was using the Arc Furnace IE multiblock to make steel, I accidentally duped IE coke dust. The steel was produced and up to half the coke dust "used" was able to be retrieved from the furnace. These items persist through server disconnects and server reboots.

Steps to reproduce the issue

1. Insert iron in Arc Furnace multiblock (preferably in multiple input slots).
2. Insert coke dust in secondary Arc Furnace input (in one input slot).
3. Power Arc Furnace to start processing iron.
4. Once iron is processing, repeatedly right-click and move the coke dust into various secondary input slots (always leaving at least one coke dust to process the iron).
5. Once the iron has finished processing, the coke dust is duplicated. This is most consistent if the coke dust has been split in half (right-click) on the tick before the iron has finished processing.

Additional Information

This was performed (accidentally, then as a test) on the Industrial Village Public Server #1 (run by dreams). No logs are available, as my game did not crash and I don't have the logs for the server. Also, the dupe is more easily achieved with a small amount of lag. A screenshot of the Arc Furnace menu has been attached to prevent a premature closing of this issue.