"Invalid" naming for extensions can cause some confusion

Situation:

• Thomas has upgraded myxwiki.org in 5.0.1
• I had the 5.0 UI installed on a subwiki
• When I went to that subwiki the DW kicked in and the attached screenshot was shown.

I was surprised to see the message "La version 5.0 installée est invalide" in red which is usually used for errors or important problems.

Is it a problem? If not, why is it in red? As a user what am I supposed to do in this case?

Thanks