When a block is broken in a layout, we show a red message as the block description:

...but there is no hint whatsoever elsewhere. I would expect that red color to "propagate" back all the way forming some sort of trail that the site admin could follow. So there should be a site status error too that triggers the admin bar red badge to show:

...and then on the manage layouts page, the layout name (and perhaps the template icon too) should also be red:

Recent comments
well @herb I cannot believe it, but the webform module was there in modules on the disc, but missing in the listed modules, so I delete the module folder, and downloaded it again. Then...
My Webform Worksheets have disappeared
The only thing I can think of is to make sure Webform module is enabled and that the content type that needs to contain the webforms has Webform enabled for it. Edit the content type and make...
My Webform Worksheets have disappeared
@yorkshirepudding, In the end I fixed it by deleting the config/active folder contents, copying the config/staging/ files into config/active, importing the database again and clearing the caches...
Importing the staged config throws an error: another field with the same name already exists