for some Reason i cant Drop items. Whatever Button i put Dropping on doesnt want to work.
i dont know if its my Controller (8BITDO SF30 PRO GAMEPAD) that i use Via a USB Cabel, or the Game just dont Wanting me to do it but i dont know lets see how it turns out.

I ran into this issue myself, and while trying to search for a solution I found this issue report. I found a solution to my problem. I had also installed the ItemPhysics Full mod. That mod was causing the problem for me.
In an instance with nothing but minecraft, forge, and controllable installed the mod worked as intended. If I simply added the ItemPhysics Full mod, that is when item dropping would stop working.

I would suggest checking your mod pack for any mods that change item dropping behavior and disabling them to see if this is the problem for you as well.

I ran into this issue myself, and while trying to search for a solution I found this issue report. I found a solution to my problem. I had also installed the ItemPhysics Full mod. That mod was causing the problem for me. In an instance with nothing but minecraft, forge, and controllable installed the mod worked as intended. If I simply added the ItemPhysics Full mod, that is when item dropping would stop working.

I would suggest checking your mod pack for any mods that change item dropping behavior and disabling them to see if this is the problem for you as well.

Guys I appreciate the info on this matter, I don't usually comment anywhere but here's what I found, in case you like the ItemPhysics Full mod, which I personally love, the issues with these mods is a specific setting which is the custom throw. On that note if you disable the custom throw setting in these two files in the config folder (itemphysic.json and itemphysic.cfg ) by setting it to false you will be able to throw items normally. That's if you're playing on 1.12.2, I haven't tried for other versions.

Hope this helps.