Title: [Plugin: W3 Total Cache] Fatal error after emptying (opcode) cache
Last modified: August 19, 2016
---
# [Plugin: W3 Total Cache] Fatal error after emptying (opcode) cache
* Resolved [taragon](https://wordpress.org/support/users/taragon/)
* (@taragon)
* [16 years, 1 month ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/)
* Hello,
* 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() [function.xcache-clear-cache]: 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,
* Cor
Viewing 15 replies - 1 through 15 (of 16 total)
1 [2](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/page/2/?output_format=md)
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* Thread Starter [taragon](https://wordpress.org/support/users/taragon/)
* (@taragon)
* [16 years, 1 month ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489023)
* Just set
* ```
Minified using disk
Page Caching using disk (enhanced)
Database Caching using xcache
```
* and things are working now brilliantly well actually.
* [Frederick Townes](https://wordpress.org/support/users/fredericktownes/)
* (@fredericktownes)
* [16 years, 1 month ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489184)
* > `Fatal error: xcache_clear_cache() [function.
> xcache-clear-cache]: 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.
* Thread Starter [taragon](https://wordpress.org/support/users/taragon/)
* (@taragon)
* [16 years, 1 month ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489185)
* 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 = ""
```
* Thread Starter [taragon](https://wordpress.org/support/users/taragon/)
* (@taragon)
* [16 years, 1 month ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489188)
* Hi Frederick,
* With some pain and effort it’s working like a charm.
* Again, much appreciated.
* [Frederick Townes](https://wordpress.org/support/users/fredericktownes/)
* (@fredericktownes)
* [16 years, 1 month ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489193)
* Great.
* [Galerio](https://wordpress.org/support/users/galerio/)
* (@galerio)
* [15 years, 10 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489298)
* [@taragon](https://wordpress.org/support/users/taragon/)
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() [function.xcache-clear-cache]: xcache.admin.user and xcache.admin.pass
is required in /home/siti/www.1e2.it/1e2.it/htdocs/wp-content/plugins/w3-total-
cache/lib/W3/Cache/Xcache.php on line 89`
* and my xcache.ini file is:
* ```
# configuration for php Xcache module
[xcache-common]
;; install as zend extension (recommended), normally "$extension_dir/xcache.so"
zend_extension = /usr/lib/php5/20060613+lfs/xcache.so
[xcache.admin]
xcache.admin.enable_auth = On
# Configure this to use admin pages
; xcache.admin.user = "mOo"
; xcache.admin.pass = md5($your_password)
; xcache.admin.pass = ""
[xcache]
; 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
[xcache.coverager]
; 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 = ""
```
* [Galerio](https://wordpress.org/support/users/galerio/)
* (@galerio)
* [15 years, 10 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489300)
* 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!
* [Frederick Townes](https://wordpress.org/support/users/fredericktownes/)
* (@fredericktownes)
* [15 years, 10 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489301)
* Thanks.
* [mikanett](https://wordpress.org/support/users/minhmeo/)
* (@minhmeo)
* [15 years, 10 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489303)
* [@galerio](https://wordpress.org/support/users/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 = ""
```
* [mikanett](https://wordpress.org/support/users/minhmeo/)
* (@minhmeo)
* [15 years, 10 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489304)
* 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](https://wordpress.org/support/users/fredericktownes/)
* (@fredericktownes)
* [15 years, 9 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489313)
* Sorry, for my part, I cannot guess other solutions without investigating on your
server. Anyone else?
* [crypted](https://wordpress.org/support/users/crypted/)
* (@crypted)
* [15 years, 8 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489321)
* 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.
* [Frederick Townes](https://wordpress.org/support/users/fredericktownes/)
* (@fredericktownes)
* [15 years, 7 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489324)
* @mikanett?
* [jgrand_idea](https://wordpress.org/support/users/jgrand_idea/)
* (@jgrand_idea)
* [15 years, 6 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489326)
* I also get the same error.
* Fatal error: xcache_clear_cache() [[function.xcache-clear-cache](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/function.xcache-clear-cache?output_format=md)]:
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?
* [jgrand_idea](https://wordpress.org/support/users/jgrand_idea/)
* (@jgrand_idea)
* [15 years, 6 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/#post-1489327)
* 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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The topic ‘[Plugin: W3 Total Cache] Fatal error after emptying (opcode) cache’ is
closed to new replies.
* 16 replies
* 6 participants
* Last reply from: [Frederick Townes](https://wordpress.org/support/users/fredericktownes/)
* Last activity: [15 years, 6 months ago](https://wordpress.org/support/topic/plugin-w3-total-cache-fatal-error-after-emptying-opcode-cache/page/2/#post-1489328)
* Status: resolved
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