the ID column should be the primary key column for the users table, this is a numeric column, not a text column.
to fix the error, double click the WAATKusers recordset. go to advanced view, and edit the ParamUserEmail parameter, change the Type from integer to text.
You kinda confused me there when you said "change the type from integer to text". But I see that you meant change the type from text to integer. Everything seems to be working now - thanks!