GlobalLock() returning NULL but NO ERROR?

[Chris8852]

I'm trying to lock a clipboard object, and GlobalLock returns NULL...
I use this to get the last error:
FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER |FORMAT_MESSAGE_FROM_SYSTEM,NULL,GetLastError(),MAKELANGID( LANG_ENGLISH, SUBLANG_ENGLISH_US ),(LPTSTR)&ptr,0, NULL);

It says "The operation completed successfully"
In other words, it's returning a NULL pointer???