I've got a weird problem with my custom inventories, for some reason when I try to left click an item to drag and drop it to its slot it pops up for like a second and then its send back into the players inventory, I first thought that it was a problem with my container but after having copied and pasted both micro's and your tutorials it resulted with same problem.
Is this problem known amongst others and is it fixable?
I can't speak for Micro's tutorials, but this particular tutorial of mine is not for copy and paste - if you copy/paste this code, chances are it will not work for you because this is not complete code.
Btw, what do you mean by 'custom inventories'? Are you sure you are in the right tutorial? This tutorial is for a multi-input / multi-output furnace type tile entity.
Does / did your container work with only one input? That would be my suggestion - get it working with one input and one output first, then expand to two when you're sure everything is working properly. That way, it's very easy to determine at which point your code breaks, and then you can troubleshoot from there.
I can't speak for Micro's tutorials, but this particular tutorial of mine is not for copy and paste - if you copy/paste this code, chances are it will not work for you because this is not complete code.
Btw, what do you mean by 'custom inventories'? Are you sure you are in the right tutorial? This tutorial is for a multi-input / multi-output furnace type tile entity.