Well, had the same problem but fixed it myself. Seems like the problem is caused by the DateTime object used in class-woothemes-updater-admin.php. Go the suggested line in the error, in the asked question it’s the line number 164:
thrown in /var/www/fs2/44/wergog/public_html/wp-content/plugins/woothemes-updater/classes/class-woothemes-updater-admin.php on line 164
Find the DateTime object and replace it as following:
\\
$date = new DateTime( parse_str($product[‘license_expiry’]) );
\\
The $product[‘license_expiry’] should be parsed as string.
That’s it. Hope it woks.