Level error?

Hi
I get this error:

[2015.08.14-06.19.12:799] 0]LogRedirectors: String Asset Reference ‘/Game/foo_forCache.foo_forCache_foo_forCache’
[2015.08.14-06.19.12:799] 0]LogRedirectors: Resolved to ‘/Game/foo_forCache.foo_forCache_foo_forCache’
[2015.08.14-06.19.12:799] 0]LogRedirectors: String Asset Reference ‘/Game/foo_forCache.foo_forCache_foo_forCache’
[2015.08.14-06.19.12:799] 0]LogRedirectors: Resolved to ‘/Game/foo_forCache.foo_forCache_foo_forCache’
[2015.08.14-06.19.12:801] 0]LogCompression:Warning: appUncompressMemoryZLIB failed: Error: Z_BUF_ERROR, not enough room in the output buffer!
[2015.08.14-06.19.12:801] 0]LogCompression:Error: FCompression::UncompressMemory - Failed to uncompress memory (14676/87380), this may indicate the asset is corrupt!
[2015.08.14-06.19.12:801] 0]LogLinux:Error: appError called: Assertion failed: Assertion failed: FCompression::UncompressMemory( Flags, Dest, Chunk.UncompressedSize, CompressedBuffer, Chunk.CompressedSize, (Padding > 0) ? true : false ) [File:/media//DATA/UnrealEngine-release/UnrealEngine/Engine/Source/Runtime/Core/Private/Serialization/Archive.cpp] [Line: 392]

[2015.08.14-06.19.13:286] 0]LogLinux: === Critical error: ===
Unhandled Exception: SIGSEGV: invalid attempt to access memory at address 0x00000003

[2015.08.14-06.19.13:286] 0]LogLinux: Assertion failed: Assertion failed: FCompression::UncompressMemory( Flags, Dest, Chunk.UncompressedSize, CompressedBuffer, Chunk.CompressedSize, (Padding > 0) ? true : false ) [File:/media//DATA/UnrealEngine-release/UnrealEngine/Engine/Source/Runtime/Core/Private/Serialization/Archive.cpp] [Line: 392]

What could that be? The fooforcache obj is not in this level. How to work with levels? How to move in game from one level(map?) to another? What are levels used for?
Many thanks