W3TC has stopped Plugins from showing. It is blank

I think I solved the problem. I went into the Database and disabled the plugin in the Options table, active_plugins field. That brought the Plugins screen back.

I deleted a:2:{i:1;s:37:"social-media-widget/social-widget.php";}

I found more problems when I tried to delete the directory. It then caused more issues. So a complete uninstall sequence:

To disable dodgy W3 Total Cache:
1. I went into the Database and disabled the plugin in the Options table, active_plugins field. That brought the Plugins screen back.
2. Delete dir /plugins/w3-total-cache to w3-total-cache.
3. In .htaaccess, remove:
# BEGIN W3TC Page Cache core
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP:Accept-Encoding} gzip
RewriteRule .* – [E=W3TC_ENC:_gzip]
RewriteCond %{REQUEST_METHOD} !=POST
RewriteCond %{QUERY_STRING} =””
RewriteCond %{REQUEST_URI} \/$
RewriteCond %{HTTP_COOKIE} !(comment_author|wp\-postpass|w3tc_logged_out|wordpress_logged_in|wptouch_switch_toggle) [NC]
RewriteCond “%{DOCUMENT_ROOT}/wp-content/cache/page_enhanced/%{HTTP_HOST}/%{REQUEST_URI}/_index.html%{ENV:W3TC_ENC}” -f
RewriteRule .* “/wp-content/cache/page_enhanced/%{HTTP_HOST}/%{REQUEST_URI}/_index.html%{ENV:W3TC_ENC}” [L]
</IfModule>
# END W3TC Page Cache core
Then upload this file to root.
4. Rename files /wp-content/advancedcache.php to advancedcache.phpBADD and objectcache.phpBADD