The semifluid generators aren't currently working properly. I can't get it to accept any fuels. I tried inserting cells of creosote oil and tried piping from the top, bottom, and all 4 of the sides. I posted this issue in the GTNH modpack's github and they said it's an issue on the mod's end. I'm playing GTNH version 2.0.9.0QF4 and I'm playing single player.

This is happening to me as well, tested with the Advanced one, and creosote cells. GTNH 2.0.9.0QF4 server, and 2.0.9.0 technic pack client.

Verified on StoneHuts 2.0.9.0 QF4 that the entire line of GT Semi-Fluid Generators will not accept any fuels - we've tried creosote, heavy fuel, oil, seed oil, light fuel.

Same goes for Large Semifluid Burner. Even Input hatch accepts fuel, Generator is not starting after hitting with Soft Mallet and fuel is not consumed.
Verified on GTNH 2.0.9.0 QF4 Single and Multi player