I deleted some files in my project with materials and so but I am not sure this is the culprit. I also changed editor versions after that. I put the files back from a local backup folder, but when I try to open some of them (material instances, animation blueprints) , the editor crashes and I get this errors:
Exception thrown at 0x00007FFF792F9CE2 (igdusc64.dll) in UE4Editor-Win64-DebugGame.exe: 0xC0000005: Access violation reading location 0xFFFFFFFFFFFFFFFF.
igdusc64.dll!00007fff792f9ce2() (Unknown Source:0)
igdusc64.dll!00007fff792f94fe() (Unknown Source:0)
igdusc64.dll!00007fff792f6c06() (Unknown Source:0)
igdusc64.dll!00007fff79269c0f() (Unknown Source:0)
igdusc64.dll!00007fff79269283() (Unknown Source:0)
igdusc64.dll!00007fff7925fcb6() (Unknown Source:0)
igdusc64.dll!00007fff7925e83b() (Unknown Source:0)
igdusc64.dll!00007fff7925e6ac() (Unknown Source:0)
igdusc64.dll!00007fff7925dc12() (Unknown Source:0)
igdusc64.dll!00007fff792157e3() (Unknown Source:0)
igdusc64.dll!00007fff79185487() (Unknown Source:0)
igdusc64.dll!00007fff7918ccde() (Unknown Source:0)
igdusc64.dll!00007fff7918e882() (Unknown Source:0)
igd10iumd64.dll!00007fff7618a45f() (Unknown Source:0)
ntdll.dll!00007fff7e9ca5b7() (Unknown Source:0)
ntdll.dll!00007fff7e9c89d7() (Unknown Source:0)
kernel32.dll!00007fff7e691412() (Unknown Source:0)
ntdll.dll!00007fff7e9a54f4() (Unknown Source:0)
Can you help me please ? Thankyou very much !