OJS website opens as a download file instead of a webpage

My OJS 3.3.0

My OJS website opens as a download file instead of a webpage

Has anyone experienced this before?

Any ideas will be appreciated, please.

Hello @williamharper

That seems like a webserver misconfiguration. Is this a new installation or the site was ok before and stopped working?

Thanks Hilongo for your reply.

No this is an old installation. The site has been up and running about a year now without any issues, until this one.