Error: Form security failed- Suddenly received this error

Hi all,

I have installed piwik-3.x. It was working till yesterday. When i tried to login on piwik, it gives error (no config changes are done)

Error: Form security failed. Please reload the form and check that your cookies are enabled. If you use a proxy server, you must configure Piwik to accept the proxy header that forwards the Host header. Also, check that your Referrer header is sent correctly.

I have checked error logs, but found nothing in it.

I had also tried to access it on other browsers, but it’s not working.

Kindly guide.

Resolved this error by renaming the old piwik folder on apache and configuring another one of same version. It took 1 min to do so.