Fatal error message

[llamasteak]

Hi there

my hosts have been migrating my website and it's come up with this error

Fatal error: Call to a member function init() on null in /home/s34yi35mlfl7/public_html/templates/rt_metropolis/error.php on line 20

It means that the template is incorrect - I'm stumped as to how to fix it. Any ideas?
It doesn't seem to be taking the template on the old server.

Please help if you can

Thanks

[gws]

I don't think your template is J 4 compatible...

[llamasteak]

Oops I've just checked... I'm running Joomla! 3.6.4 Stable.

I think it should run with that shouldn't?

[Per Yngve Berg]

Mod. Note: Relocated topic from J4 to J3 forum.

[Per Yngve Berg]

The current version is 3.10.11. J3.6.4 is not compatible with current versions of php.

[llamasteak]

looks like I'm running php 5.6.40