[TYPO3-mvc] The value must be of type "Extension_model_name", but was of type "NULL".

[Alisha]

Hi,
i have a model eith 1 property and 3 relations (1:1).
the edit-form throw the error

The value must be of type "..Domain_Model_Couples", but was of type "NULL"

also if the form is almost empty :
<f:form method="post" action="update" name="couples" object="{couples}">
<f:form.textfield property="nummer" /><br />	
<f:form.submit class="btn" value="anmelden" />
</f:form>

I'm going crazy because I dont find the error:-(
my getNummer() and setNummer() are okay..
i can debug the object in the template and its okay too.

in the exception its called a method "setCouples("") with empty 
parameters, but my class is called "couples" , i have no property with 
this name. may have something to do with the error?


the last lines of exceptions:
33 Tx_Extbase_MVC_Controller_Argument::transformValue("")


..\extbase\Classes\MVC\Controller\Argument.php:

00349:    $this->value = $value;
00350:   } else {

00351:    $this->value = $this->transformValue($value);

00352:   }
00353:   return $this;


32 Tx_Extbase_MVC_Controller_Argument::setValue("")


H:\Programme\xampp\htdocs\typo3\salsa\typo3\sysext\extbase\Classes\MVC\Controller\Arguments.php:

00225:   if (in_array($firstLowerCaseArgumentName, 
$this->getArgumentNames())) {
00226:    $argument = parent::offsetGet($firstLowerCaseArgumentName);

00227:    $argument->setValue($arguments[0]);

00228:   } elseif (in_array($firstUpperCaseArgumentName, 
$this->getArgumentNames())) {
00229:    $argument = parent::offsetGet($firstUpperCaseArgumentName);


31 Tx_Extbase_MVC_Controller_Arguments::__call("setCouples", array)

30 Tx_Extbase_MVC_Controller_Arguments::setCouples("")

29 call_user_func(array, "")

Thank you for help!