Error 500 when activating Brotli

Hello @teknisa

Thank you for your inquiry and I am happy to assist you with this.
I just want to clarify that after adding this to our list of issues, Gido Manders checked the issue and gave the appropriate reply. This being said it’s a matter of a mod conflict so you are using another mod that requires BROTLI instead of what we are using and that’s BROTLI_COMPRESS.
I am leaving the quoted explanation here for your convenience:

The reason we use AddOutputFilterByType BROTLI_COMPRESS and AddOutputFilter BROTLI_COMPRESS, is because the Apache website suggests it:
https://httpd.apache.org/docs/trunk/mod/mod_brotli.html

You are probably using another mod that requires BROTLI instead. You could switch mods or disable the brotli option in the browser cache settings and add the code for brotli to your .htaccess file outside of the W3TC blocks.

We check for the PHP function brotli_compress, because that function is used to compress cache files and store a compressed version of the cache, same as we do for gzip compression. If we would not do this, the server has to dynamically compress files when requested, which takes some time. That would defeat the purpose of using compression to speed up the website.

If you want to use the Apache module only, which I do not recommend, you could always add the required code manually to your .htaccess file outside of the W3TC blocks.

Thanks for the answer.

I removed all modules and redid the installation by following this step by step.

https://design.briarmoon.ca/tutorials/drupal/setting-up-the-brotli-extension-for-php

Worked perfectly. I hope this topic resolves once and for all the doubts of anyone who had or will have this error.

I understand that after activating Brotli on W3, W3 will create the files and send them to CDN, am I right?

Also, you need to do some configuration in Performance >> CDN >> Advanced >> Custom file list?

Hello @teknisa

Sorry for the late reply. NO there is no need for any additional configuration.
Thank you!