SQL cannot cast string value "TRUE" to boolean, So use 1 for true and 0 for false. In your code change like this,,
If WhereCondition = "" Then
Qry = "SELECT " & ColumnName & " FROM " & TabelName & " WHERE (isDeleted = 1) ORDER BY " & ColumnName
Else
Qry = "Select " & ColumnName & " From " & TabelName & " Where (isDeleted = 1) And " & WhereCondition & " Order By " & ColumnName
End If
if the column is of type bit/boolean then 1 and 0 will treated as true and false respectively.