i've tried to research this here and across the web and i've found a few solutions, but the ones i've understood and tried have not worked.
our Wordpress-based site (www.tarakmc.org) recently became inaccessible: browsers simply displayed a blank white page. i was unable to log in to Wordpress. i looked in CPanel and saw that all the files and folders were still there so, not knowing what to do, i contacted our host company ezpzhosting. Dan from ezpz kindly took a look and identified that the file wp-includes/pluggable.php had somehow become corrupted (no-one here had edited it - we have no php knowledge!) he replaced this file with the version from the default Wordpress package and this appeared to fix the issue - browsers now display the site as expected.
however, when we now try to login to wordpress in order to update posts etc. we all get the same error: "You do not have sufficient permissions to access this page." this is the same for administrator accounts. i'm unsure which version of Wordpress we have installed (as i can't login to the Dashboard!) but in general we try to keep it, and our plugins and themes etc., up to date, so it will be the latest or nearly the latest.
i have seen a lot of people online having similar issues over the years and a common solution appears to be disabling plugins by renaming wp-content/plugins, creating a new plugins folder, and moving first the index.php file and then the plugin folders from the renamed plugins-disabled folder into the plugins folder. people said that this enabled them to identify a plugin which was causing the issue.
our site is dependent on a few plugins in order to display correctly. nevertheless, i tried the above suggestion but it did not resolve the problem. even with an empty plugins folder, or only index.php in it, any and all attempts to login still produce the same error. therefore i'm not sure that the issue in this case is being caused by a plugin.
we're a UK registered charity and our site is quite big and complicated. we have several other sites in add-on domains. i *really* do not feel confident, or have the time it would take, to reinstall Wordpress and rebuild the site a piece at a time! if anyone can suggest how to identify what has gone wrong and how to fix it i'd be extremely grateful!
