Please Help - Fatal Error

Has anyone seen this before and/or knows how to fix it?
My project has been working fine but for some reason now when I open the level I have been working on Unreal crashes. I have tried different machines with the same result. I will post the error below:

LoginId:f2cd4b0a4948c17e5d6305b145c83756
EpicAccountId:ea900c791a3e42bcab74f120f96d1816

Fatal error: [File:D:\Build++UE4+Release-4.18+Compile\Sync\Engine\Source\Runtime\Core\Private\Serialization\Archive.cpp] [Line: 550] BulkData compressed header read error. This package may be corrupt!

UE4Editor_Core!FArchive::SerializeCompressed() [d:\build++ue4+release-4.18+compile\sync\engine\source\runtime\core\private\serialization\archive.cpp:561]
UE4Editor_CoreUObject!FUntypedBulkData::SerializeBulkData() [d:\build++ue4+release-4.18+compile\sync\engine\source\runtime\coreuobject\private\serialization\bulkdata.cpp:1245]
UE4Editor_CoreUObject!FUntypedBulkData::AsyncLoadBulkData() [d:\build++ue4+release-4.18+compile\sync\engine\source\runtime\coreuobject\private\serialization\bulkdata.cpp:707]
UE4Editor_CoreUObject!FStateComplete::FStateComplete() [d:\build++ue4+release-4.18+compile\sync\engine\source\runtime\coreuobject\private\serialization\bulkdata.cpp:598]
UE4Editor_CoreUObject!FUntypedBulkData::LoadBulkDataWithFileReader() [d:\build++ue4+release-4.18+compile\sync\engine\source\runtime\coreuobject\private\serialization\bulkdata.cpp:610]
UE4Editor_Engine!FTextureCacheDerivedDataWorker::FTextureSourceData::GetAsyncSourceMips() [d:\build++ue4+release-4.18+compile\sync\engine\source\runtime\engine\private\texturederiveddatatask.cpp:122]
UE4Editor_Engine!FTextureCacheDerivedDataWorker::DoWork() [d:\build++ue4+release-4.18+compile\sync\engine\source\runtime\engine\private\texturederiveddatatask.cpp:306]
UE4Editor_Engine!FAsyncTask::DoWork() [d:\build++ue4+release-4.18+compile\sync\engine\source\runtime\core\public\async\asyncwork.h:264]
UE4Editor_Engine!FAsyncTask::DoThreadedWork() [d:\build++ue4+release-4.18+compile\sync\engine\source\runtime\core\public\async\asyncwork.h:288]
UE4Editor_Core!FQueuedThread::Run() [d:\build++ue4+release-4.18+compile\sync\engine\source\runtime\core\private\hal\threadingbase.cpp:451]
UE4Editor_Core!FRunnableThreadWin::Run() [d:\build++ue4+release-4.18+compile\sync\engine\source\runtime\core\private\windows\windowsrunnablethread.cpp:76]