[TYPO3-formidable] backend module

[Domi Garms]

Good Morning formidables,

I just try for using formidable in a backend module, but it doesnt
work. My error:

t3lib_cache_exception_DuplicateIdentifier

A cache with identifier "tx_extbase_cache_reflection" has already been
registered.

What has tx_extbase to do with this? And I am not sure how to set the
main function right...Here is where I want to place my formidable form
but I just gave up because of the Error-Message:

index.php

case 1:
							$content='<div align="center"><strong>Hello World!</strong></div><br />
								The "Kickstarter" has made this module automatically, it
contains a default framework for a backend module but apart from that
it does nothing useful until you open the script
'.substr(t3lib_extMgm::extPath('dmf_aupairs'),strlen(PATH_site)).'mod1/index.php
and edit it!
								<hr />
								<br />This is the GET/POST vars sent to the script:<br />'.
								'GET:'.t3lib_div::view_array($_GET).'<br />'.
								'POST:'.t3lib_div::view_array($_POST).'<br />'.
								'';
							$ressourceFile = "test.xml";
							$this->oForm = t3lib_div::makeInstance("tx_ameosformidable");
							$this->oForm->init(
							        $this,
							        t3lib_extmgm::extPath($this->extKey) .
"ressources/xml/" . $ressourceFile
							    );
							    return $this->oForm->render();
							tx_ameosformidable::backendHeaders(&$this);
							$this->content.=$this->doc->section('Message #1:',$content,0,1);
						break;

Thanks for any help!

Regards,

Domi