Level editor "Black Box" problem

[Your Computer]

How can i "verify the game cache" , since it's the level editor , not Amnesia ?

Through Steam. There's a reason why you can't place the HPL2 suite tools anywhere but where Amnesia is installed. This is because the tools make use of many of the same libraries that the game uses. The log showed that many entity caches were "out of date". I find this to be a bit odd and wonder what else is out of date.