Crash when I try to open my Level

Hello everyone !

I got a huge problem… when I create a new level, everything works fine, I can open it, place character, etc…
But when I close the editor and I open it the next day, the level won’t open anymore and the editor crash.
He send me this message :

Assertion failed: false [File:D:\UE4\UnrealEngine\Engine\Source\Runtime\Engine\Private\UnrealEngine.cpp] [Line: 9658]

KERNELBASE.dll!UnknownFunction (0x00007ff80b62a1c8) + 0 bytes [UnknownFile:0]
UE4Editor-Core.dll!UnknownFunction (0x00007ffff5a809a4) + 0 bytes [UnknownFile:0]
UE4Editor-Core.dll!UnknownFunction (0x00007ffff59989a8) + 0 bytes [UnknownFile:0]
UE4Editor-Core.dll!UnknownFunction (0x00007ffff5964942) + 0 bytes [UnknownFile:0]
UE4Editor-Engine.dll!UnknownFunction (0x00007fffe38a32d8) + 0 bytes [UnknownFile:0]
UE4Editor-Engine.dll!UnknownFunction (0x00007fffe3894e95) + 0 bytes [UnknownFile:0]
UE4Editor-ShooterGame.dll!APrimalDinoCharacter::GetAimOffsets() (0x00007fffdd21de59) + 0 bytes [d:\ue4\unrealengine\projects\shootergame\source\shootergame\private\primaldinocharacter.cpp:2608]
UE4Editor-ShooterGame.dll!APrimalCharacter::execGetAimOffsets() (0x00007fffdd6f54ed) + 525 bytes [d:\ue4\unrealengine\projects\shootergame\source\shootergame\classes\primalcharacter.h:28]
UE4Editor-CoreUObject.dll!UnknownFunction (0x00007ffff550fc64) + 0 bytes [UnknownFile:0]
UE4Editor-CoreUObject.dll!UnknownFunction (0x00007ffff5581e7a) + 0 bytes [UnknownFile:0]
UE4Editor-CoreUObject.dll!UnknownFunction (0x00007ffff55ad742) + 0 bytes [UnknownFile:0]
UE4Editor-CoreUObject.dll!UnknownFunction (0x00007ffff55aeb6e) + 0 bytes [UnknownFile:0]
UE4Editor-CoreUObject.dll!UnknownFunction (0x00007ffff558239a) + 0 bytes [UnknownFile:0]
UE4Editor-CoreUObject.dll!UnknownFunction (0x00007ffff55aeb6e) + 0 bytes [UnknownFile:0]
UE4Editor-CoreUObject.dll!UnknownFunction (0x00007ffff550fc64) + 0 bytes [UnknownFile:0]
UE4Editor-CoreUObject.dll!UnknownFunction (0x00007ffff55ae363) + 0 bytes [UnknownFile:0]
UE4Editor-Engine.dll!UnknownFunction (0x00007fffe404671a) + 0 bytes [UnknownFile:0]
UE4Editor-Engine.dll!UnknownFunction (0x00007fffe3ab7c45) + 0 bytes [UnknownFile:0]
UE4Editor-Engine.dll!UnknownFunction (0x00007fffe36d95d2) + 0 bytes [UnknownFile:0]
UE4Editor-Engine.dll!UnknownFunction (0x00007fffe36b9f36) + 0 bytes [UnknownFile:0]
UE4Editor-Engine.dll!UnknownFunction (0x00007fffe36bef2c) + 0 bytes [UnknownFile:0]
UE4Editor-Engine.dll!UnknownFunction (0x00007fffe3135fe0) + 0 bytes [UnknownFile:0]
UE4Editor-Engine.dll!UnknownFunction (0x00007fffe31686ce) + 0 bytes [UnknownFile:0]
UE4Editor-Engine.dll!UnknownFunction (0x00007fffe3155d6d) + 0 bytes [UnknownFile:0]
UE4Editor-Engine.dll!UnknownFunction (0x00007fffe3500e37) + 0 bytes [UnknownFile:0]
UE4Editor-Engine.dll!UnknownFunction (0x00007fffe352b31b) + 0 bytes [UnknownFile:0]
UE4Editor-Engine.dll!UnknownFunction (0x00007fffe3996daa) + 0 bytes [UnknownFile:0]
UE4Editor-UnrealEd.dll!UnknownFunction (0x00007fffe71fc945) + 0 bytes [UnknownFile:0]
UE4Editor-UnrealEd.dll!UnknownFunction (0x00007fffe71c34d7) + 0 bytes [UnknownFile:0]
UE4Editor-CoreUObject.dll!UnknownFunction (0x00007ffff5580034) + 0 bytes [UnknownFile:0]
UE4Editor-CoreUObject.dll!UnknownFunction (0x00007ffff55edf6b) + 0 bytes [UnknownFile:0]
UE4Editor-CoreUObject.dll!UnknownFunction (0x00007ffff55f8d4d) + 0 bytes [UnknownFile:0]
UE4Editor-CoreUObject.dll!UnknownFunction (0x00007ffff560044b) + 0 bytes [UnknownFile:0]
UE4Editor-CoreUObject.dll!UnknownFunction (0x00007ffff5605704) + 0 bytes [UnknownFile:0]
UE4Editor-ContentBrowser.dll!UnknownFunction (0x00007fffdc2640b7) + 0 bytes [UnknownFile:0]
UE4Editor-ContentBrowser.dll!UnknownFunction (0x00007fffdc2bb702) + 0 bytes [UnknownFile:0]
UE4Editor-ContentBrowser.dll!UnknownFunction (0x00007fffdc247633) + 0 bytes [UnknownFile:0]
UE4Editor-ContentBrowser.dll!UnknownFunction (0x00007fffdc2512a8) + 0 bytes [UnknownFile:0]
UE4Editor-ContentBrowser.dll!UnknownFunction (0x00007fffdc2c7994) + 0 bytes [UnknownFile:0]
UE4Editor-ContentBrowser.dll!UnknownFunction (0x00007fffdc240706) + 0 bytes [UnknownFile:0]
UE4Editor-ContentBrowser.dll!UnknownFunction (0x00007fffdc24f30b) + 0 bytes [UnknownFile:0]
UE4Editor-ContentBrowser.dll!UnknownFunction (0x00007fffdc24c9f6) + 0 bytes [UnknownFile:0]
UE4Editor-ContentBrowser.dll!UnknownFunction (0x00007fffdc2dc84f) + 0 bytes [UnknownFile:0]
UE4Editor-ContentBrowser.dll!UnknownFunction (0x00007fffdc2c7bdf) + 0 bytes [UnknownFile:0]
UE4Editor-Slate.dll!UnknownFunction (0x00007ffff4fcc4f5) + 0 bytes [UnknownFile:0]
UE4Editor-Slate.dll!UnknownFunction (0x00007ffff4fb848b) + 0 bytes [UnknownFile:0]
UE4Editor-Core.dll!UnknownFunction (0x00007ffff5a03abc) + 0 bytes [UnknownFile:0]
UE4Editor-Core.dll!UnknownFunction (0x00007ffff59e8d1b) + 0 bytes [UnknownFile:0]
UE4Editor-Core.dll!UnknownFunction (0x00007ffff5a04dc9) + 0 bytes [UnknownFile:0]
UE4Editor-Core.dll!UnknownFunction (0x00007ffff59e41b2) + 0 bytes [UnknownFile:0]
USER32.dll!UnknownFunction (0x00007ff80ded00dc) + 0 bytes [UnknownFile:0]
USER32.dll!UnknownFunction (0x00007ff80decfc07) + 0 bytes [UnknownFile:0]
UE4Editor-Core.dll!UnknownFunction (0x00007ffff5a05286) + 0 bytes [UnknownFile:0]
UE4Editor.exe!UnknownFunction (0x00007ff714a39242) + 0 bytes [UnknownFile:0]
UE4Editor.exe!UnknownFunction (0x00007ff714a2ed0f) + 0 bytes [UnknownFile:0]
UE4Editor.exe!UnknownFunction (0x00007ff714a2ed7a) + 0 bytes [UnknownFile:0]
UE4Editor.exe!UnknownFunction (0x00007ff714a3aa60) + 0 bytes [UnknownFile:0]
UE4Editor.exe!UnknownFunction (0x00007ff714a3b999) + 0 bytes [UnknownFile:0]
KERNEL32.DLL!UnknownFunction (0x00007ff80d502d92) + 0 bytes [UnknownFile:0]
ntdll.dll!UnknownFunction (0x00007ff80e169f64) + 0 bytes [UnknownFile:0]
ntdll.dll!UnknownFunction (0x00007ff80e169f64) + 0 bytes [UnknownFile:0]

My project and the editor are on the disk E but he tell me that I got a prob on the disk D, wich is attributed to nothing.

Do someone already got this error ? How can I repair it ?

PS : I am really sorry if my english is bad, but it is not my native language