An error occurred while updating the launcher.

[Desecrated7]

When running, it returns an error, all DLS, even those that are included in the standard edition, are shown as "not authentic"

*tap*

In the screenshot: An error occurred while updating the launcher. Please contact customer support

 

[Veltri]

Same as you.
I got all DLC and run on Steam in Ubuntu 20.04 (Linux)

"An error occurred while updating the launcher"

 

[Philologer]

It sometimes happens to me also, but I just reopen launcher and the message is gone.

 

[Desecrated7]

The restart didn't help, it started after I completely deleted HOI4 from the computer.