Object Required

I'm getting this error and don't know why:

Microsoft VBScript runtime error '800a01a8'

Object required

The line points to where the query takes place. I've read that it could be b'cos a variable that's not defined, but this is not the case, not that i know. Here's the line:

rs4.Open strsqlttype, connStr, adOpenForwardOnly, adLockReadOnly, adCmdTableDirect

strsqlttype is the variable wish contains the select, and it is initialized as empty. After running the query on the database i found some empty/null records, b'cos of that i validate the fields i need... prior that it stoped right after the loop writes the first line, after validation was placed it stoped on the second record.