TYPO3: Backend Module linking action of another Controller

I created a simple backend module for TYPO3 (7.6.15), with help of the ExtensionBuilder. The UserController and MediaController have a createAction, showAction and listAction. The PanelController just has the showAction which is the main view of the module.

Now I want to link actions from the other controllers in the template of the showAction. The content of the view for the PanelController.showAction (MyExt/Resources/Private/Templates/Panel/Show.html) is the following:

<f:layout name="Default" />
<f:section name="content">
  <f:flashMessages />
  <f:link.action action="create" controller="User">Create new User</f:link.action>
  <f:link.action action="create" controller="Media">Create new Media</f:link.action>
</f:section>

If clicked on one of the links, I get: "Could not analyse class: "MyExt\MyExt\Controller\UserController" maybe not loaded or no autoloader? Class MyExt\MyExt\Controller\UserController does not exist", as error.

I already tried to add plugin.tx_myext.callDefaultActionIfActionCantBeResolved = 1 to the setup.ts and load the other controllers in the initializeAction, but nothing worked so far.

I appreciate all help in advance and wish everyone a nice day!

Solution

I just had a misspelled function that crashed all, unfortunately TYPO didn't give the correct error message. This and checking the database for errors with the install tool fixed it.