3.7 Problem. Blank page for usercp.php and private.php

[Tortikova]

I have problem.
I have forum: 3.7 Gold
my account: Sample1
I'm log in to my account and all pages OK with two exeption:
usercp.php and private.php show blank page.

This problem for only account: "Sample1". This account haves additional Administration group.

But another accounts (ANY) don't have problems.

What is this? Please, help.

Error code:

PHP Fatal error: Unsupporte d operand types in /var/home/www/....../www/includes/functions_user.php on line 227

I'm looking functions_user.php.
line 227:

$pmfolders = $pmfolders + unserialize($vbulletin->userinfo['pmfolders']);

Other code:

// get PM folders
$cpnav['pmfolders'] = '';
$pmfolders = array('0' => $vbphrase['inbox'], '-1' => $vbphrase['sent_items']);
if (!empty($vbulletin->userinfo['pmfolders']))
{
$pmfolders = $pmfolders + unserialize($vbulletin->userinfo['pmfolders']);
}
foreach ($pmfolders AS $folderid => $foldername)
{
$linkurl = 'private.php?' . $vbulletin->session->vars['sessionurl'] . "folderid=$folderid";
eval('$cpnav[\'pmfolders\'] .= "' . fetch_template('usercp_nav_folderbit') . '";');
}