View not rendered properly when HTML 5.0 Syntax is disabled.

When using the "Enable the rendered diff view" option, the display is messy when HTML 5.0 syntax is disabled.

All available syntaxes are disabled except for XWiki 2.1. This means that the rendered view of the Change Request Application is unable to render correctly.

If HTML 5 syntax is enabled, the view is rendered correctly. Is there an option to display the preview or rendered view correctly even when HTML 5 syntax is disabled, e.g., using XWiki 2.1 syntax?

The wrongly rendered view looks like this: