In a managed_file upload field, how do I prevent an overflow with long file names? I have a form using the field type of managed_upload. Things are working fine accept when the file name is long. 



Given the snippet of code, below. Might there be a way to override CSS or inject any CSS to keep the fieldset or this span from overrunning the sidebar_second region?

  $form['file_fs'] = array(
    '#type' =&gt; 'fieldset',
    '#title' =&gt; t('Files'),
    '#collapsible' =&gt; FALSE,
    '#collapsed' =&gt; FALSE,
  );

  $form['file_fs']['file'] = [
    '#title' =&gt; t('Documents'),
    '#type' =&gt; 'managed_file', ,
    '#upload_location' =&gt; 'private://',

  ];
I would suggest adding a class to the fieldset and adding a class to the css file of your theme.

Add something like this to the fieldset.

'#attributes' =&gt; array('class' =&gt; array('my-fieldset'));

And then something like this to your css file

.my-fieldset {max-width: 100%;}