Epic Games\UE_4.21\Engine\Source\Runtime\Core\Public\Android\AndroidString.h
static FORCEINLINE int64 Strtoi64( const WIDECHAR* Start, WIDECHAR** End, int32 Base )
{
int StartLen = Strlen(Start);
ANSICHAR* AnsiStart = (ANSICHAR*)FMemory_Alloca(StartLen+1);
CopyWideToAnsi(AnsiStart, Start);
ANSICHAR* AnsiEnd = NULL;
uint64 Res = strtoll(AnsiStart, &AnsiEnd, Base);
should change uint64 to int64