[TYPO3] Back end goes blank

[Bing Du]

>> Bing Du wrote:
>>> Hi,
>>>
>>> Typo3 4.0.6
>>>
>>> The back end went blank again today.  Again, manually deleting the
>>> temp_CACHED_* files in typo3conf/ brought it back.  I checked the
>>> typo3conf/localconf.php file and noticed the last change was made on
>>> 5/23/2007.  I've seen the problem twice in the past couple of years.
>>> Can
>>> anybody shed some light on what might be going on?  How and why
>>> temp_CACHED_* files prevent back end from showing up?
>>>
>>> Thanks in advance,
>>>
>>> Bing
>>>
>> Hi,
>>
>> We have a similar problem a two moths ago in typo 4.1 , BE went blank
>> instead to show a error message when we  have a error in the code. But
>> we have
>>
>> We resolved this setting $TYPO3_CONF_VARS['SYS']['displayErrors'] = '1'
>> in localconf.php.
>>
>> Regards.
>>
>> Iván Gómez Rodríguez
>> Ingeniero en Informática
>> mailto:igomez at igalia.com
>> Telf:  +34 986 10 76 10
>> Fax:   +34 981 91 39 49
>> Igalia http://www.igalia.com
>>
>>
>
> That's a good hint.  Thanks.  Besides showing the error right up front on
> the page, were you also able to find it in any logs, say Apache error log
> file?  My concern with showing error message on the page is it could
> reveal system config or file structure information.  This time, since I
> already deleted temp_CACHED_* files and the back end came back up, I was
> not able to catch the error on the page.  I'll try it next time.
>
> Bing

I checked Apache ssl_error_log and found

[client <my desktop IP>] PHP Warning:  Cannot modify header information -
headers already sent by (output started at
/var/www/html/top/typo3conf/temp_CACHED_psad09_ext_tables.php:4470) in
/var/www/html/typo3_src-4.0.6/t3lib/class.t3lib_userauth.php on line 314,
referer: https://sitelogin.some.edu/cgi-bin/index.cgi
[client <my desktop IP>] PHP Warning:  Cannot modify header information -
headers already sent by (output started at
/var/www/html/top/typo3conf/temp_CACHED_psad09_ext_tables.php:4470) in
/var/www/html/typo3_src-4.0.6/typo3/index.php on line 473, referer:
https://sitelogin.some.edu/cgi-bin/index.cgi

I wonder if that tells something?  We use pubcookie for single sign on.

Bing