Issue deploying a custom page layout: Only Content controls are allowed directly in a content page that contains Content controls

Just for your information:

I recently had an issue deploying a custom page layout. The error was the following:

Only Content controls are allowed directly in a content page that contains Content controls

It showed that it had something to do with the case of asp:content tags. The "C" needs to be in Upper case.

<asp:Content> instead of <asp:content>

I was lucky that I found this blogpost. Funny is that this post is already 6 years old :-)

http://blog.consejoinc.com/2009/01/sharepoint-page-layout-error-only.html

Cheers

Sven