Drupal 8.x

I am sure it must be possible but I cannot find a way to display a calendar in Drupal 8 showing 6 months at a time.  Can anyone point me in  the right direction please?   

I'm having problem with Drupal 8 view. I made view a with custom table data. I used hook_views_data() and I can see all the results from the custom table. Now I would like to add relationships to another table but I am not seeing any available relationships on the views GUI. I have added the following code:

Hello everybody! I use Drupal since version 4 for a lot of my customers. With Drupal 7 I can do almost everything, handle big data on thousands of nodes and so on. 

I have to start a new big project and decided to have a look at Drupal 8. Now the point is: should I use D8 in this new project? After a week of tests I cannot use "rules" at their best but I've seen the newly "Action" module. I can't find a lot of "familiar" things that I've used to use in Drupal 7, but D8 development is still growing and a lot of modules are becoming available day by day.

After updating from drupal 8.4.5 to  8.5.4 I am getting this error. 

The website encountered an unexpected error. Please try again later.</br></br><em class="placeholder">InvalidArgumentException</em>: Field  is unknown. in <em class="placeholder">Drupal\Core\Entity\ContentEntityBase-&gt;getTranslatedField()</em> (line <em class="placeholder">580</em> of <em class="placeholder">core/lib/Drupal/Core/Entity/ContentEntityBase.php</em>).

What can be the issue?

Thanks

Dear community,

actually I've a problem with creating a block view. I don't want to write code for that and hope it can be done with settings within the view.

I've a taxonomy with regions and a content type with a single taxonomy reference field.

On top of that I've another content type referencing the same taxonomy. I want to use that content type to show all nodes, which are references same taxonomy.

I am trying to implement the bootstrap 3 class listed below in a bootstrap 3 subtheme so I can make my embeds responsive. Every time I add the class below it causes my embeds to disappear. Where would I place these classes in a bootstrap 3 theme subtheme?

These are the classes from the bootstrap website:

<!-- 16:9 aspect ratio -->
<div class="embed-responsive embed-responsive-16by9">
  <iframe class="embed-responsive-item" src="..."></iframe>
</div>

This is my template file: field--iframe.html.twig