composer & php 5.6.26 & ubuntu: curl is missing from your system

sudo apt-get install php5.6-curl
sudo a2enmod proxy_fcgi setenvif
sudo a2enconf php5.6-fpm
sudo service apache2 reload

helped notices from php5.6-cur installing

Dr Web blocked my HOSTS file, how to fix?

Just reboot system and have access to read/write in it

symfony fixtures cannot delete or update a parent row

* you can add to problem entity field, which is described in error onDelete="set null"

* or deny to purge your database, add to your command key --append.

Unable to find mapping information for the class Context

Need to fully configure sonata-classification-bundle, its needed for modern versions of sonata-media.

admin_sonata_classification_context_create" as such route does not exist in SonataAdminBundle:Core:add_block.html.twig

just cache:clear and cache:clear -e prod

5 columns layout with Twitter Bootstrap

based on http://www.wearesicc.com/quick-tips-5-column-layout-with-twitter-bootstrap/ , modified for fitting 5 columns in any >320px width displays.

.col-xs-15,
.col-sm-15,
.col-md-15,
.col-lg-15 {
  position: relative;
  min-height: 1px;
  padding-right: 10px;
  padding-left: 10px;
}

@media (min-width: 320px) {
  .col-md-15 {
    width: 20%;
    float: left;
  }
}

And use it like this:

<div class="col-md-15 col-sm-3">
    ...
</div>

how to fix Symfony CSRF token is invalid. Please try to resubmit the form

If you have problems with uploading files, you should not disable  CSRF, only fix it with this hints:

* make sure in php.ini (in all directories in /etc/php5/) max_post_size much bigger than upload_size.
* do not forget to restart server (apache or nginx) and "service php5-fpm restart"