Joomla 3.8 with PHP 7problems

I'm currently in the forced transition from PHP 5.6 to 7.1 (or 7.2, both are an option) for my website. I have two websites, the one is working fine but the other isn't running on 7.1 or .2.

I get the following error messages:

[Thu Oct 25 09:25:21.985120 2018] [:error] [pid 12006] PHP Deprecated: Non-static method Joomla\\CMS\\Application\\CMSApplication::getMenu() should not be called statically, assuming $this from incompatible context in /home/public/sites/www.modderaandebanden.nl/libraries/src/Application/SiteApplication.php on line 275
[Thu Oct 25 09:25:21.985130 2018] [:error] [pid 12006] PHP Strict Standards: Only variables should be assigned by reference in /home/public/sites/www.modderaandebanden.nl/templates/siteground-j16-1/templates.php on line 15

Can anybody tell me what's going on here. Is it the template that's not suited to usage with PHP 7?

Thanks in advance