Can't figure this out for the life of me. Why am I getting an Object Require Error with the following code:

 
Set WbAgg = ThisWorkbook
Set WsAggChrt = WbAgg.Sheets("Chart Data")
Set Period1 = WsAggChrt.Range("M2")
Set Period2 = WsAggChrt.Range("M3")
Set Period3 = WsAggChrt.Range("M4")
The error is generated with Period3. Isn't the object already set with the line Set WbAgg = ThisWorkbook?

Thanks,

Sirius