PHP7 update causes 502 Bad Gateway

I ran a test on a non critical site.

ee site update site.com --php7

The result was a 502 bad gateway.

I was able to turn off php7 and get the site back.

Any ideas on what to look for?

This was a WordPress site with wpredis.

Hello,

Check the logs :

cat /var/www/nginx/yourwebsite.com.error.log