Hi Becky, I don’t know if you’ve seen some of the other posts today but there appears to be an issue with the latest version of Wordfence on sites hosted on Windows servers.
In the short term you’ll need to access the wp-content/plugins/ folder via an FTP client and rename the Wordfence folder. This should then get any affected sites back up and running.
I have posted this on another thread, but it is only those sites on Windows hosting that have been affected by this problem for.
Updating to the latest version of Wordfence on Linux isn’t an issue.
Just wanted to confirm that the same is the case for me: only sites on Windows are affected by the update.