An error occurred during local report processing.
An error has occurred during report processing.
The Group expression used in grouping 'table1_month' returned a data type that is not valid.

1.  An error occurred during local report processing. 
2.  An error has occurred during report processing. 
3.  The Group expression used in grouping 'table1_month' returned a data type that is not valid. 

SELECT
	CONCAT(MONTHNAME(t1.Date), ' ', YEAR(t1.Date)) Month,
	SUM(IF(t1.VisitorBrowser='MSIE', 1, 0)) 'IE',
	SUM(IF(t1.VisitorBrowser='Firefox', 1, 0)) 'FF',
	SUM(IF(t1.VisitorBrowser='Safari', 1, 0)) 'CS',
	SUM(IF(t1.VisitorBrowser='Smartphone', 1, 0)) 'Smart',
	SUM(IF(t1.VisitorBrowser='Other', 1, 0)) 'Other',
	COUNT(t1.VisitorBrowser) 'Total'
FROM
(SELECT
	a.DateTimeStamp Date,
	CASE
		WHEN INSTR(a.VisitorUAgent, 'MSIE ') THEN 'MSIE'
		WHEN INSTR(a.VisitorUAgent, 'Firefox') THEN 'Firefox'
		WHEN INSTR(a.VisitorUAgent, 'Safari') THEN 'Safari'
		WHEN INSTR(a.VisitorUAgent, 'Chrome') THEN 'Safari'
		WHEN INSTR(a.VisitorUAgent, 'BlackBerry') THEN 'Smartphone'
		WHEN INSTR(a.VisitorUAgent, 'iPhone') THEN 'Smartphone'
		WHEN INSTR(a.VisitorUAgent, 'Android') THEN 'Smartphone'
		WHEN INSTR(a.VisitorUAgent, 'NetFront') THEN 'Smartphone'
		WHEN INSTR(a.VisitorUAgent, 'SonyEricsson') THEN 'Smartphone'
		ELSE 'Other'
	END VisitorBrowser
FROM
	custombu_stats_visits a
GROUP BY
	a.VisitorIP
ORDER BY
	a.DateTimeStamp DESC) t1
GROUP BY
	CONCAT(MONTH(t1.Date), ' ', YEAR(t1.Date))

1.  SELECT 
2.      CONCAT(MONTHNAME(t1.Date), ' ', YEAR(t1.Date)) Month, 
3.      SUM(IF(t1.VisitorBrowser='MSIE', 1, 0)) 'IE', 
4.      SUM(IF(t1.VisitorBrowser='Firefox', 1, 0)) 'FF', 
5.      SUM(IF(t1.VisitorBrowser='Safari', 1, 0)) 'CS', 
6.      SUM(IF(t1.VisitorBrowser='Smartphone', 1, 0)) 'Smart', 
7.      SUM(IF(t1.VisitorBrowser='Other', 1, 0)) 'Other', 
8.      COUNT(t1.VisitorBrowser) 'Total' 
9.  FROM 
10.  (SELECT 
11.      a.DateTimeStamp Date, 
12.      CASE 
13.          WHEN INSTR(a.VisitorUAgent, 'MSIE ') THEN 'MSIE' 
14.          WHEN INSTR(a.VisitorUAgent, 'Firefox') THEN 'Firefox' 
15.          WHEN INSTR(a.VisitorUAgent, 'Safari') THEN 'Safari' 
16.          WHEN INSTR(a.VisitorUAgent, 'Chrome') THEN 'Safari' 
17.          WHEN INSTR(a.VisitorUAgent, 'BlackBerry') THEN 'Smartphone' 
18.          WHEN INSTR(a.VisitorUAgent, 'iPhone') THEN 'Smartphone' 
19.          WHEN INSTR(a.VisitorUAgent, 'Android') THEN 'Smartphone' 
20.          WHEN INSTR(a.VisitorUAgent, 'NetFront') THEN 'Smartphone' 
21.          WHEN INSTR(a.VisitorUAgent, 'SonyEricsson') THEN 'Smartphone' 
22.          ELSE 'Other' 
23.      END VisitorBrowser 
24.  FROM 
25.      custombu_stats_visits a 
26.  GROUP BY 
27.      a.VisitorIP 
28.  ORDER BY 
29.      a.DateTimeStamp DESC) t1 
30.  GROUP BY 
31.      CONCAT(MONTH(t1.Date), ' ', YEAR(t1.Date)) 

CONCAT(MONTHNAME(t1.Date), ' ', YEAR(t1.Date)) AS Month

1.  CONCAT(MONTHNAME(t1.Date), ' ', YEAR(t1.Date)) AS Month 

t1.Date AS Month

1.  t1.Date AS Month