Drupal 8.x

This question is regarding a module I plan to develop as a Google Summer of Code participant, if I get selected for the program. For seeing the complete project idea details, please refer to this: https://groups.drupal.org/node/508466#project30

I can't even view the reports, so I am not sure how to access the log files to give more details. But it happened when I (rather stupidly) tried to install two Drupal 8 installations under localhost to host two different sites, both started showing this error message since then. I had Drupal 7 and Drupal 8 installation under localhost and it was working all right. So, I thought that two different Drupal 8 installation will also work fine but apparently it didn't.

When displaying a view of teaser i would like to also show a sidebar with some filters so we can filter the display by checking or unchecking the checkbox in front of the filters. Should i use taxonomies for that ? Or the filter option in view is different ? Can you just tell me where to look for the best practice ? :)

Thank you.

Hi everyone, i do have a form associated to my content type, i added a checkbox in this form so when i add an entry i can check the checkbox if i want display a certain image on my template or not. How do i do the test like

{% if content.field_myCheckbox is checked}

{% endif %}

Thanks in advance :)

Validate user Login form with username, Email address , and password. So i need to store their email address in the same table where username and password stores. And say email address is the secondary email address (another email address) which is entered by the users via a separate form. Any suggestion or code snippet is appreciable.

From the Drupal 8 docs: "You enable Twig Debugging in sites/default/services.yml.
(If services.yml does not yet exist; copy default.services.yml and rename it to services.yml.)"

I don't have a service.yml only a default.services.yml

Why is this file set to read only if I need to copy it? Is it safe to change it to read and write?