Breaking: #78759 - Fluidification of EditFileController

See Issue #78759

Description

While moving all HTML from PHP code to an own Fluid template the HTML string given to the hook after compiling the output is different now.

Impact

The HTML string given to the hook after compiling the output now contains the closing form tag (</form>).

Affected Installations

All installations that append text to the HTML code in the hook after compiling the output.

Migration

The hook code has to be changed to insert additional code before the closing form tag.