Steps to reproduce the issue

Hello everyone

I can't copy site template or administrator template, I have an error :

JInstaller: :Install: File does not exist /home/bruno28/sites/joomla4beta1/tmp/template_copy_5e355972ce9ee/language
Template Install: Could not copy files from the files source.

and

Error installing template
Unable to install new template from temporary folder.

My temporary folder has 755 read/write property

Expected result

Copy of (Cassiopea and Atum) to override them

Actual result

Error

System information (as much as possible)

Joomla 4.0.0-beta1-dev

Additional comments