Looking for some PHP migration advice

Hi WebDevs!

I'm new in my role at my current place and part of my job is converting existing PHP apps into ASP.NET apps. No problem with that, it's what I do. However these PHP apps are on an old server which management wants decommissioned yesterday because the OS is massively out of date.

If I can figure out a way of migrating these applications onto a more up to date server, even on a temporary basis, then it would reduce a huge amount of pressure on the work I do converting these applications.

I've already attempted moving them over and all attempts have been unsuccessful so far. The problem is PHP is well out of comfort zone and whenever I do the smallest amount of work on them, they fall apart. They're very old and struggle with dependency errors whenever you try and update them.

They're currently sat on a 2008 box running ZendServer (they're ZF apps), ZendServer license has expired so I can't access it. All I've got is the files themselves.

Can anyone offer any insight? Is a migration even going to be possible in your opinion?

Thanks!