EFG Module: Warning too few arguments

Hello,
I am using contao 2.10 and I've recently installed efg extension.

When I want to see Form data, there are 2 warnings and i can't see the data. The warnings are the following:

1) vsprintf() [function.vsprintf]: Too few arguments in ...\system\drivers\DC_Formdata.php
2)Cannot modify header information - headers already sent by (...\system\functions.php:164) in ...\system\libraries\Template.php

The first warning seems to be a problem with the label's lenght. The error comes from this section of the DC_Formdata.php file:

Code:

---

// Shorten label it if it is too long

                                $label = vsprintf((strlen($GLOBALS['TL_DCA'][$this->strTable]['list']['label']['format']) ? $GLOBALS['TL_DCA'][$this->strTable]['list']['label']['format'] : '%s'), $args);



                                if (strlen($GLOBALS['TL_DCA'][$this->strTable]['list']['label']['maxCharacters']) && $GLOBALS['TL_DCA'][$this->strTable]['list']['label']['maxCharacters'] < strlen($label))

                                {

                                        $this->import('String');

                                        $label = trim($this->String->substrHtml($label, $GLOBALS['TL_DCA'][$this->strTable]['list']['label']['maxCharacters'])) . ' …';

                                }

---

I was looking for this error on the web and there are some solutions, but they don't work for me. I also use characters like % () and /on the labels but I removed them and the problem is still there. Does anybody knows if there is a maximum number of characters for the labels? some of my labels are a bit long 30 or 40 characteres.

I've solved the problem, it's not possible to write the % symbol in the field name.

Thank you!