Cannot access empty property

[pein87]

It depends on what your trying to do to understand more you would need to look at the classes themselves to see what each one is capable of doing. Its the same in desktop programming if you make a call to a class but it doesnt support the fuctionality your looking for it will more then likely not work unless you make a if condition to test if it supports what your trying to do. vbulletin is the main class and I'm sure db is made to handel the lesser query tasks.