[TYPO3] can't add content

[Wail]

Thank you for your reply.
I did that several times. Every time I do:
Install Tool->Database Analyser->Update required tables->COMPARE

I get

Changing fields
[ ]	ALTER TABLE tx_dbal_debuglog CHANGE script script varchar(255) NOT NULL;
	Current value: varchar(255) default ''
[ ]	ALTER TABLE tx_dbal_debuglog CHANGE serdata serdata BLOB;
	Current value: blob

I check both boxes and click on "Write to database" button. But nothing 
changes, I still get the same screen with the same check boxes!

Franz Holzinger wrote:
>> I upgraded from typo3 3.8.1 to 4.0.
>> Now I can't add any content to my page.
>>
>> If I want to add a page, I get error "2: SQL error: 'Column 'media'
>> cannot be null' (pages:NEW4456904932364)"
>>
>> If I want to add a simple text pagecontent to one of the page, I get
>> error "2: SQL error: 'Column 'l18n_diffsource' cannot be null'
>> (tt_content:NEW4456914b57817)"
>>
> Use the install tool and check all your database tables.
> 
> - Franz
>