Fill in the script on this page in DotNetNuke --> Host --> SQL and you can see how large every mssql table filesize is. If you database is larger than 100MB than it is highly recommended to open your database with  Microsoft SQL management studio and right-click on your databasefile and go to tasks --> shrink (both database and files). Now your website will be much faster because it has been cleaned. It will be also smart to go to administrator --> event viewer to see if you have any log errors from lets say module failures, to maybe see where errors may come from. Succes.

BEGIN try
DECLARE @table_name VARCHAR(500) ;
DECLARE @schema_name VARCHAR(500) ;
DECLARE @tab1 TABLE(
        tablename VARCHAR (500) collate database_default
,       schemaname VARCHAR(500) collate database_default
);
DECLARE  @temp_table TABLE (   
        tablename sysname
,       row_count INT
,       reserved VARCHAR(50) collate database_default
,       data VARCHAR(50) collate database_default
,       index_size VARCHAR(50) collate database_default
,       unused VARCHAR(50) collate database_default
);

INSERT INTO @tab1
SELECT t1.name
,       t2.name
FROM sys.tables t1
INNER JOIN sys.schemas t2 ON ( t1.schema_id = t2.schema_id );  

DECLARE c1 CURSOR FOR
SELECT t2.name + '.' + t1.name 
FROM sys.tables t1
INNER JOIN sys.schemas t2 ON ( t1.schema_id = t2.schema_id );  

OPEN c1;
FETCH NEXT FROM c1 INTO @table_name;
WHILE @@FETCH_STATUS = 0
BEGIN 
        SET @table_name = REPLACE(@table_name, '[','');
        SET @table_name = REPLACE(@table_name, ']','');

        -- make sure the object exists before calling sp_spacedused
        IF EXISTS(SELECT OBJECT_ID FROM sys.objects WHERE OBJECT_ID = OBJECT_ID(@table_name))
        BEGIN
                INSERT INTO @temp_table EXEC sp_spaceused @table_name, false ;
        END
       
        FETCH NEXT FROM c1 INTO @table_name;
END;
CLOSE c1;
DEALLOCATE c1;
SELECT t1.*
,       t2.schemaname
FROM @temp_table t1
INNER JOIN @tab1 t2 ON (t1.tablename = t2.tablename )
ORDER BY  schemaname,tablename;
END try
BEGIN catch
SELECT -100 AS l1
,       ERROR_NUMBER() AS tablename
,       ERROR_SEVERITY() AS row_count
,       ERROR_STATE() AS reserved
,       ERROR_MESSAGE() AS data
,       1 AS index_size, 1 AS unused, 1 AS schemaname
END catch