Warning: array_merge() [function.array-merge]: Argument #1 is not an array

Modify the tinybrowser.php (line #1153 or somewhere nearby) to change
From:
'#attributes' => array('class' => 'tinybrowser-weight'),
To:
'#attributes' => array('class' => array('tinybrowser-weight')),

Here's the extract of the function tinybrowser_role_form() where you need to modify.
I hope this will fix the issue.

Before (tinybrowser.php)

/**
 * Role profile form
 */
function tinybrowser_role_form($role, $weight = TRUE, $core = TRUE) {
  $form['name'] = array(
    '#type' => 'item',
    '#markup' => $role['name'],
  );
  if ($weight) {
    $form['weight'] = $core ? array(
      '#type' => 'textfield',
      '#value' => $role['weight'],
      '#attributes' => array('readonly' => 'readonly', 'style' => 'border:none; width: 2em; background-color: tran
sparent;'),
    ) : array(
      '#type' => 'weight',
      '#default_value' => $role['weight'],
      '#attributes' => array('class' => 'tinybrowser-weight'),
    );
  }
  $options = array(t('none'));
  foreach (variable_get('tinybrowser_profiles', array()) as $pid => $profile) {
    $options[$pid] = $profile['name'];
  }
  $form['pid'] = array(
    '#type' => 'select',
    '#options' => $options,
    '#default_value' => $role['pid'],
  );
  return $form;
}

After

/**
 * Role profile form
 */
function tinybrowser_role_form($role, $weight = TRUE, $core = TRUE) {
  $form['name'] = array(
    '#type' => 'item',
    '#markup' => $role['name'],
  );
  if ($weight) {
    $form['weight'] = $core ? array(
      '#type' => 'textfield',
      '#value' => $role['weight'],
      '#attributes' => array('readonly' => 'readonly', 'style' => 'border:none; width: 2em; background-color: tran
sparent;'),
    ) : array(
      '#type' => 'weight',
      '#default_value' => $role['weight'],
      '#attributes' => array('class' => array('tinybrowser-weight')),
    );
  }
  $options = array(t('none'));
  foreach (variable_get('tinybrowser_profiles', array()) as $pid => $profile) {
    $options[$pid] = $profile['name'];
  }
  $form['pid'] = array(
    '#type' => 'select',
    '#options' => $options,
    '#default_value' => $role['pid'],
  );
  return $form;
}