### Steps to reproduce

1. Login to QA Edge and Begin of the insertionopen a work packageEnd of the insertion Begin of the deletion go to Administration/Custom fieldsEnd of the deletion

2. Begin of the insertionClickEnd of the insertion Begin of the deletion Look at the "Contained in type" column and select one of the custom fields that haven't been added to a wp type yet -> clickEnd of the deletion on Begin of the insertionWorkEnd of the insertion Begin of the deletion Add thisEnd of the deletion field Begin of the deletion to a work package typeEnd of the deletion

3. Begin of the insertionEnter any value in Work fieldEnd of the insertion Begin of the deletion When available types open, click on a type

4. Open the configuration form tab

5. Drag the cf from right to leftEnd of the deletion and Begin of the insertionpress Save (alternatively: goEnd of the insertion Begin of the deletion drop itEnd of the deletion to Begin of the insertionAdministration/Work packages/Types/Task and pressEnd of the insertion Begin of the deletion any section

6. End of the deletion Save Begin of the insertionthere)End of the insertion


### What is the buggy behavior?

* Begin of the insertionValueEnd of the insertion Begin of the deletion ThereEnd of the deletion is Begin of the insertionnot savedEnd of the insertion Begin of the deletion no success messageEnd of the deletion and Begin of the insertionerror inEnd of the insertion Begin of the deletion reloadingEnd of the deletion the Begin of the insertionconsoleEnd of the insertion Begin of the deletion page gives 404 The page you were trying to access doesn't exist or has been removed

* Custom field has not been added to the work package type (confirmed on checking the work package creation page)End of the deletion


Begin of the insertion<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/400234/content">

End of the insertion ### What is the expected behavior?

1. Begin of the insertionSaveEnd of the insertion Begin of the deletion UserEnd of the deletion should Begin of the deletion be able to add the cf to aEnd of the deletion work Begin of the insertionand not return any errorsEnd of the insertion Begin of the deletion package typeEnd of the deletion


### Environment information

**OpenProject version**

Core build

[4aa610a1c88795260947f934b7a6896ce21f2a71](https://github.com/opf/openproject/commits/4aa610a1c88795260947f934b7a6896ce21f2a71)

Product version

[4b55c8485559fa6ad277e54aea2b97536297836d](https://github.com/opf/saas-openproject/commits/4b55c8485559fa6ad277e54aea2b97536297836d)

Core version

OpenProject 15.5.0