Adding SSL to site breaks plugin upload script

I’m using ‘Ultimate Member’ plugin which includes the feature for users to upload their own avatar. After installing SSL, the upload feature results in a ‘INTERNAL SERVER ERROR’. The plugin support suggested I allow access for the plugin source files in the conf file. Not sure if this is my solution, however wanted to rule it out.

I’ve followed the instructions from the Nginx Includes page, however have no experience in doing so.

I’ve created the file in the trellis directory:
with contents:

location {{ www_root }}/ {
  allow all;

This hasn’t helped at all - please help…

  1. Is my conf file actually correct?
  2. What else could cause this issue to occur?