---
title: "TYPO3 Exception 1278450972"
manual: "TYPO3 Exceptions"
version: "main"
permalink: "https://docs.typo3.org/permalink/t3exceptions:typo3-exception-1278450972"
source: "Exceptions/1278450972.rst"
rendered: "2026-09-24T13:19:33+00:00"
---

# TYPO3 Exception 1278450972 {#typo3-exception-1278450972}

> [!NOTE]
> Below, the TYPO3 community may have provided additional information or
> solutions for this exception. However, these may or may not apply to your
> particular case. If you can provide more information, you should come back
> here and add your experience and solution steps to this issue once you have
> resolved it.
>
> General TYPO3 troubleshooting tips can be found in the *Troubleshooting*
> section in the menu. You can also ask questions and receive support in the
> [TYPO3 Questions category on talk.typo3.org](https://talk.typo3.org/c/typo3-questions/).
>
> To add your experience, click "Edit on GitHub" above and follow the
> ["Edit on GitHub" workflow](https://docs.typo3.org/m/typo3/docs-how-to-document/main/en-us/Howto/EditOnGithub.html#docs-contribute-github-method).
> Also check out
> [our tip on Coding Style and reST](https://docs.typo3.org/permalink/t3exceptions:tip-about-rest-coding-style).

## #1278450972: Class ... does not exist. Reflection failed. TYPO3 9.5 {#1278450972-class-does-not-exist-reflection-failed-typo3-9-5}

We had a whitespace at the beginning of the filename of the file containing
the class.

When switching over from working with TYPO3 v10+ back to TYPO3 v9.5, remember that you have to
specify the fully qualified name for parameters, as opposed to TYPO3 v10+ where you can import
the class name.

## #1278450972: Class ... does not exist. Reflection failed. After updating to TYPO3 11 {#1278450972-class-does-not-exist-reflection-failed-after-updating-to-typo3-11}

We missed the required update in the registration of plugins and modules to use the full class name.

See [Breaking: #92609 - Use controller classes when registering plugins/modules](https://docs.typo3.org/c/typo3/cms-core/main/en-us/Changelog/11.0/Breaking-92609-UseControllerClassesWhenRegisteringPluginsmodules.html).

## #1278450972: Class ... does not exist. Reflection failed. in TYPO3 11 {#1278450972-class-does-not-exist-reflection-failed-in-typo3-11}

Running `composer update` fixes the problem in a Composer based installation of TYPO3.

## #1278450972: The classname "..." was not found and thus can not be reflected. {#1278450972-the-classname-was-not-found-and-thus-can-not-be-reflected}

This (extbase) error can occur if you have annotated a (controller
action) method using `@param` but have not given it a type hint. If the
annotation is wrong this error will occur.

Example:

```
/**
 * A test action
 *
 * @param \MyVendor\MyExtension\Domain\Motel\InvalidName $myVariable
 */
public function testAction($myVariable) {

```

As you see the `@param` annotation is wrong. Because you usually have not
any `DomainMotel` namespace and there is no type hint for $myVariable
in the function header.

So either correct the annotation, clear all caches:

```
/**
 * A test action
 *
 * @param \MyVendor\MyExtension\Domain\Model\ValidName $myVariable
 */
public function testAction($myVariable) {

```

Or try to add a type hint:

```
/**
 * A test action
 *
 * @param \MyVendor\MyExtension\Domain\Model\ValidName $myVariable
 */
public function testAction(\MyVendor\MyExtension\Domain\Model\ValidName $myVariable) {

```

I had a Composer based Installation. And i have to add my ext. to the
psr4 autoload in copmposer.json:

```
"autoload": {
     "psr-4": {
             "MyVendor\\MyExtension\\":"web/typo3conf/ext/MyExtension/Classes"
     }
 },

```

## #1278450972 TYPO3CMSExtbaseReflectionExceptionUnknownClassException {#1278450972-typo3-cms-extbase-reflection-exception-unknownclassexception}

**Class Boolean does not exist. Reflection failed.**

```
at TYPO3\CMS\Extbase\Reflection\ReflectionService->buildClassSchema('Vendorname\\Extensionname\\Domain\\Model\\MyModel')

```

Got this error because in MyModel was a setter with a wrong typehint, in
my case it was something like

```
public function setFreeShipping(\Boolean $freeShipping)

```

Solution was to change *\\Boolean* to *bool*.