PHP output buffering : ob_get_clean(): Failed to discard buffer of ob_gzhandler" whilst buffer has been set

Question

Good day,

I am getting the following error in PHP :

ob_get_clean(): Failed to discard buffer of ob_gzhandler 

I am developing an application under Windows WAMPServer. And I have tried to launch my application today. Unfortunately the first thing I got was content encoding error. Whilst it worked perfectly under WAMP with the following code :

///########-------------------------------------------------------------
///########-------------------------------------------------------------
///######## METHOD : PARSE TEMPLATE
///########-------------------------------------------------------------
///########-------------------------------------------------------------
private static function parse($tpl){
    ///######## TURN ON OUTPUT BUFFER
    ob_start(null, 32768);
    ///######## ENABLE GZIP ENCODING
    ob_start("ob_gzhandler");
    ///######## ENABLE CACHING
    header('Cache-Control: public');
    ///######## EXPIRES IN ONE {x} SECONDS, {default 86400 seconds (seven days)}
    if(self::$cache_expire) header('Expires: '.gmdate('D, d M Y H:i:s', time() + self::$cache_expire).' GMT');
    ///######## ECHO CODE
    echo $tpl;
    ///######## GET THE OUTBUT BUFFER
    $tpl = ob_get_clean();
    ///######## FLUSH BUFFER
    ob_end_flush();



    ///########==================================================
    ///######## PARSED CODE
    ///########==================================================
    return $tpl;
    ///########==================================================
}

This gave under Linux Centos and PHP 8.1 a content encoding error. A little digging on this forum gave me the following :

PHP Output buffering, Content Encoding Error caused by ob_gzhandler?

So I changed my code to :

///########-------------------------------------------------------------
///########-------------------------------------------------------------
///######## METHOD : PARSE TEMPLATE
///########-------------------------------------------------------------
///########-------------------------------------------------------------
private static function parse($tpl){
    ///######## TURN ON OUTPUT BUFFER
    ob_start(null, 32768);
    ///######## ENABLE GZIP ENCODING
    ob_start("ob_gzhandler");
    ///######## ENABLE CACHING
    header('Cache-Control: public');
    ///######## EXPIRES IN ONE {x} SECONDS, {default 86400 seconds (seven days)}
    if(self::$cache_expire) header('Expires: '.gmdate('D, d M Y H:i:s', time() + self::$cache_expire).' GMT');
    ///######## ECHO CODE
    echo $tpl;
    ///######## FLUSH
    ob_flush();
    ///######## GET THE OUTBUT BUFFER
    $tpl = ob_get_clean();



    ///########==================================================
    ///######## PARSED CODE
    ///########==================================================
    return $tpl;
    ///########==================================================
}

That gives me a little more. But unfortunately still an error :

Notice: ob_get_clean(): Failed to discard buffer of ob_gzhandler

Now I have been looking at the examples over and over again.

I found the following thread : failed to delete buffer. No buffer to delete

But the point is. There actually is buffer to clean. So that couldn't be the issue.

Where could my error be?

SOLUTION

I had :

    ///######## TURN ON OUTPUT BUFFER
    ob_start(null, 32768);
    ///######## ENABLE GZIP ENCODING
    ob_start("ob_gzhandler");

But I should switch these two. Why exactly this is. I don't know. But maybe if someone wants. Add the explanation. But for reference. I still add this "question" so that someone doesn't have to spend a frustrating evening.

    ///######## ENABLE GZIP ENCODING
    ob_start("ob_gzhandler");
    ///######## TURN ON OUTPUT BUFFER
    ob_start(null, 32768);

*please close this question