Also BIG Problems with X and updated cornerstone: all links to blogposts don't work anymore! (resolved)

Hello,
I have also BIG problems with the new (updated) cornerstone and X and need help urgently!!!

Edit: I could resolve it by delete the X and re-install it, now there is only a small problem: my sidebar don’t shows up on my pages!

the Problem was:
All Links to the blog posts don’t work anymore. There is only this message on a blank page:

“Fehlendes Template. Eigenständige Themes müssen über eine index.php Datei verfügen. Für Child-Themes muss ein Template-Header in der style.css angelegt werden.”

Translated in english: “Template is missing. Independet Themes must have an index.php file. For child-Themes there must be added a template-header in the style.sss”

The Links in the masonry are made with The grid or Essential grid. All plugins and also WP is the newest.

I don’t know NOTHING about css and code, and I NEVER created a child theme!!! so PLEASE can anybody help me? its VERY urgent!
Also I wonder where the selection of the type of page is gone (e.g. blank container, with or without header / footer etc.,)there are no mor selectable.

Thank you, greetings from Switzerland
Nicole

I just had a client call me freaking out that their blog posts were not showing on the front-end, but you can see all content on the backend …this only happened after the cornerstone latest update.

We updated x-theme and it all worked perfectly. I hope that yours is as easy as this to solve.

Thank you! I did the same now - delete it and re-install, and it works again.

only my sidebar dont show up anymore …

Hi There,

I Checked your website and the sidebar is being shown on your blog posts.

Can you clarify where you wants it to appear?

On the pages you want it to appear you can try accessing the page, clicking edit page > under the blue update button you will find > Page Attributes > Page Templates > Select Default.

Hope it helps