Support » Plugins » [Plugin: W3 Total Cache] Fatal error after emptying (opcode) cache

  • Resolved Taragon



    After having set both Page Caching and Minify to Opcode: XCache (somehow my host doesn’t support APC) I keep getting this error after emptying all or opcode only cache:
    Fatal error: xcache_clear_cache() [<a href='function.xcache-clear-cache'>function.xcache-clear-cache</a>]: unexpect 8 bytes of xcache.admin.pass, expected 32 bytes, the password after md5() in /home/design24/public_html/wp-content/plugins/w3-total-cache/lib/W3/Cache/Xcache.php on line 89
    Does someone might know what I might be overlooking here?

    Best regards,


Viewing 15 replies - 1 through 15 (of 16 total)
  • Just set

    Minified using disk
    Page Caching using disk (enhanced)
    Database Caching using xcache

    and things are working now brilliantly well actually.

    Fatal error: xcache_clear_cache() [<a href='function.xcache-clear-cache'>function.xcache-clear-cache</a>]: unexpect 8 bytes of xcache.admin.pass, expected 32 bytes, the password after md5() in /home/design24/public_html/wp-content/plugins/w3-total-cache/lib/W3/Cache/Xcache.php on line 89

    Wrong xcache.ini setting: xcache.admin.pass should be md5 hash of password and 32 symbols length.

    Hi Frederick, I now realize this as well. Could you tell how to set/reset this?

    ;xcache.admin.user = "admin"
    ;xcache.admin.pass	= ""
    ;xcache.admin.enable_auth = On
    xcache.test = Off
    xcache.coredump_directory = ""

    Hi Frederick,

    With some pain and effort it’s working like a charm.

    Again, much appreciated.


    can you also explain us how have you resolved your issue?

    I have a similar issue too, but I don’t know what to do.

    My error is:
    Fatal error: xcache_clear_cache() [<a href='function.xcache-clear-cache'>function.xcache-clear-cache</a>]: xcache.admin.user and xcache.admin.pass is required in /home/siti/ on line 89

    and my xcache.ini file is:

    # configuration for php Xcache module
    ;; install as zend extension (recommended), normally "$extension_dir/"
    zend_extension = /usr/lib/php5/20060613+lfs/
    xcache.admin.enable_auth = On
    # Configure this to use admin pages
    ; xcache.admin.user = "mOo"
    ; xcache.admin.pass = md5($your_password)
    ; xcache.admin.pass = ""
    ; ini only settings, all the values here is default unless explained
    ; select low level shm/allocator scheme implemenation
    xcache.shm_scheme =        "mmap"
    ; to disable: xcache.size=0
    ; to enable : xcache.size=64M etc (any size > 0) and your system mmap allows
    xcache.size  =                16M
    ; set to cpu count (cat /proc/cpuinfo |grep -c processor)
    xcache.count =                 1
    ; just a hash hints, you can always store count(items) > slots
    xcache.slots =                8K
    ; ttl of the cache item, 0=forever
    xcache.ttl   =                 0
    ; interval of gc scanning expired items, 0=no scan, other values is in seconds
    xcache.gc_interval =           0
    ; same as aboves but for variable cache
    xcache.var_size  =            0M
    xcache.var_count =             1
    xcache.var_slots =            8K
    ; default ttl
    xcache.var_ttl   =             0
    xcache.var_maxttl   =          0
    xcache.var_gc_interval =     300
    xcache.test =                Off
    ; N/A for /dev/zero
    xcache.readonly_protection = Off
    ; for *nix, xcache.mmap_path is a file path, not directory.
    ; Use something like "/tmp/xcache" if you want to turn on ReadonlyProtection
    ; 2 group of php won't share the same /tmp/xcache
    ; for win32, xcache.mmap_path=anonymous map name, not file path
    xcache.mmap_path =    "/dev/zero"
    ; leave it blank(disabled) or "/tmp/phpcore/"
    ; make sure it's writable by php (without checking open_basedir)
    xcache.coredump_directory =   ""
    ; per request settings
    xcache.cacher =               On
    xcache.stat   =              Off
    xcache.optimizer =           Off
    ; per request settings
    ; enable coverage data collecting for xcache.coveragedump_directory and xcache_coverager_start/stop/get/clean() functions (will hurt executing performance)
    xcache.coverager =          Off
    ; ini only settings
    ; make sure it's readable (care open_basedir) by coverage viewer script
    ; requires xcache.coverager=On
    xcache.coveragedump_directory = ""

    Here is the solution:
    uncomment the line with ;xcache.admin.enable_auth = On (that is remove the ; at the beginning) and change the option to Off. The result must be:
    xcache.admin.enable_auth = Off

    And now it works!


    @galerio: i tried your solution but it still error.

    ;xcache.admin.user = "admin"
    ;xcache.admin.pass      = ""
    xcache.admin.enable_auth = Off
    xcache.test = Off
    xcache.coredump_directory = ""

    I tried again

    nano /etc/php5/cgi/conf.d/xcache.ini

    xcache.admin.enable_auth = Off

    Not found error, but when i add new post, it cannt save draft (always: Saving Draft… )

    Frederick Townes


    Sorry, for my part, I cannot guess other solutions without investigating on your server. Anyone else?

    This is probably silly, but when you edited the xcache.ini and saved it with the auth to OFF setting… did you restart apache?
    “/etc/init.d/apache2 restart”

    I had the same problem you were having. So, I edited the xcache.ini and restarted the httpd server, no problems working swell.


    I also get the same error.

    Fatal error: xcache_clear_cache() [function.xcache-clear-cache]: xcache.admin.user and xcache.admin.pass is required in …line 89.

    While the site is working, I cannot add/edit post and do a whole bunch of stuff.

    Too bad I do not know php or how to edit the xcache.ini. I paid host to install and make the modifications but I don’t know why they can’t modify the portion where you could turn the admin.user off.

    What I did was to comment out the function up to line 89. And the errors all went away.

    Question is: Is it ok to comment out that particular function? What would be the subsequent effect? Anyone knows what that particular function is for? The php line goes

         * Flushes all data
         * @return boolean
        /**function flush()
            xcache_clear_cache(XC_TYPE_VAR, 0);
            return true;

    I have the above disabled, what would happen?

    my host, probably exasperated over my lack of knowledge installed xcache.ini in w3tc directory. I tried editing files to no avail. The same error appears when I publish or update blogs or empty caches. Although, changes are nonetheless made in updated blogs even when the error appears. Anyone having the same problem?

Viewing 15 replies - 1 through 15 (of 16 total)
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