Just to add further to this, if I remove the file advanced-cache.php (which the error code is mentioning) and also the object-cache.php file, then I can log in to the dashboard however my website displays the following errors in the header both in the dashboard and also live on the website:
Warning: include(/websites/123reg/LinuxPackage23/ox/an/ad/oxanadodon.com/public_html/conservatoryonlineprices/wp-content/advanced-cache.php) [function.include]: failed to open stream: No such file or directory in /websites/123reg/LinuxPackage23/ox/an/ad/oxanadodon.com/public_html/conservatoryonlineprices/wp-settings.php on line 58
Warning: include() [function.include]: Failed opening ‘/websites/123reg/LinuxPackage23/ox/an/ad/oxanadodon.com/public_html/conservatoryonlineprices/wp-content/advanced-cache.php’ for inclusion (include_path=’.:/usr/local/php52/share/pear:/usr/local/php52/share/php’) in /websites/123reg/LinuxPackage23/ox/an/ad/oxanadodon.com/public_html/conservatoryonlineprices/wp-settings.php on line 58
Warning: Cannot modify header information – headers already sent by (output started at /websites/123reg/LinuxPackage23/ox/an/ad/oxanadodon.com/public_html/conservatoryonlineprices/wp-settings.php:58) in /websites/123reg/LinuxPackage23/ox/an/ad/oxanadodon.com/public_html/conservatoryonlineprices/wp-includes/option.php on line 568
Warning: Cannot modify header information – headers already sent by (output started at /websites/123reg/LinuxPackage23/ox/an/ad/oxanadodon.com/public_html/conservatoryonlineprices/wp-settings.php:58) in /websites/123reg/LinuxPackage23/ox/an/ad/oxanadodon.com/public_html/conservatoryonlineprices/wp-includes/option.php on line 569
What can I do to get rid of this issue?
You should never delete pieces of this plug in, it puts stuff in too many places and you WILL have a broken site by deleting only some. It heavily modifies .haccess as well.
Your best bet would have been to enable debug in WP (in config.php) and post the error messages you got.
Now you put yourself in a less than pretty situation.
Your best bet is to restore the bits you have removed, and post the errors you get with debug activated.
Ok I have restored to elements I have deleted and the site appears to be working fine now.
How do you suggest I remove this plugin?
Also I am using a shared hosting account, when you say that the plugin heavily modifies .haccess is this only for the actual file within this particular web directory for this website? Or would this plugin have affected other websites running under the same hosting packages but in different folders on different databases within the hosting package?
To remove W3TC I suggest you to:
1) Check with utmost attention that the files you restored are under the same owner of the other files in your website.
I.e. if all the files in your websites are owned by: “john www-data”, the restored files MUST be owned by “john www-data” and attribute 664 or 666. Attribute and owner are made visible by most decent FTP programs like Filezilla.
2) Really make sure you have done step 1, I am serious.
3) Empty all caches by using the W3TC menu at the top of the WP admin screen.
4) Backup the website both files and database
5) Only then, deactivate the plug in and then delete its files only through the WP uninstaller. If you get any “chmod error” or “access denied” etc. it means you did not do your homeworks at point 1.
6) Check the .htaccess that is in your website root. Website root may be your www root or a subdirectory if you installed WP in a subdirectory. If you still see comments containing “W3 Total Cache” or “W3 TC” (comments = text lines starting with a “#” sign) then for some reason W3TC could not write the file. You have to open the file and remove the stuff between the comments, you may have several sequences of comments … code /end of section …. random code used by other plug ins …. more W3 TC code.
Once you have removed all of this, the website should work again.
If you get errors 500 or 404 it means the uninstall did not go clean. In that case if you don’t want to ask for 3rd party support you are better to re-reinstall W3 TC and see if the website works if you leave W3TC disabled.
Can’t really tell you more without seeing the situation or knowing about your web host. Sadly many web hosts are truly terrible for anything more evolved than the most basic WP installation.