Unreal crash at 18% even after deleting projects and redownloading the engine

I am using Unreal to build a sample game for a scholarship and now it is broken. I was making the project when i decided that i had reached the end of my productivity so i decided to start a new project to unwind and build some landscapes but unreal crashed when i tried to open it. i figured it was something to do with how i had two instances running(the original project and the new one) so i saved and closed the original project and tried again with the same result. i then figured it was something to do with my old project so i tried moving and temporarily deleting my project but had the same result so i made a backup of my project and deleted it from the projects page in the epic games launcher but it still crashed at 18 percent. i was getting desperate so i re downloaded the entire engine and now it still has the same crash. the crash screen says this:

Assertion failed: SerializeNum >= 0 [File:D:\Build\++UE4+Licensee\Sync\Engine\Source\Runtime\Core\Public\Containers/Array.h] [Line: 1152]

UE4Editor_Core
UE4Editor_Core
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_Core
UE4Editor_Core
UE4Editor_Core
UE4Editor_Core
UE4Editor_Engine
UE4Editor
UE4Editor
UE4Editor
UE4Editor
UE4Editor
kernel32
ntdll

the crash has never varied regardless of what i do
any suggestions or fixes?

I am getting the same error

Assertion failed: SerializeNum >= 0
[File:D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Public\Containers/Array.h]
[Line: 1152]

UE4Editor_Core UE4Editor_Core
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_DerivedDataCache
UE4Editor_Core UE4Editor_Core
UE4Editor_Core UE4Editor_Core
UE4Editor_Engine UE4Editor UE4Editor
UE4Editor UE4Editor UE4Editor kernel32
ntdll

Hey not sure if you guys are still having this issue, but I’ve found something that fixed it for me. In the file explorer go to Appdata → local → Unreal engine-> 4.25. Then once there delete the derived data cache folder.Then when you launch UE4 it shouldn’t crash.
Hope this helps.

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