wp-admin suddenly displaying 'page not found'

Address to the site?

Try renaming the plugins directory. Create a new empty pugins directory with the same permissions as the old.

Sorry for not getting back to you all. I contacted my webhost and they resolved the issue.

Ive got the same problem. how do i fix this?

@pmargolin
You should start a new topic.

I’m not sure what caused it exactly – they made some changes to the security on their server. It was them who broke it.

Are you having the same problem? You did not mark this topic as resolved.
Hosts sometimes apply updates that while fixing some issues create new ones. Would not neccessarily lay too much blame.