[CI2.1.4] This page isn’t working website is currently unable to handle this request.

Otherwise, you're stuck in the PHP 5.3/5.4 ish which is not ideal.

Not true, CI version 2.2.2 works just fine running on PHP 5.6.30
We still use it for small websites. To be fair we do now update core file as CI 2.x.x is no longer supported.

And any problems under 5.6.30 were quick to fix