Misplacement of objects in container/skin after upgrade to DNN 9.1.1

Issue

In DNN 8.X there is a common practice that results in a problem when you upgrade to Evoq 9.1.1.
In the /Admin screen, it is possible to choose the Themes option and then scroll down to select options in this screen, to be able to select one custom theme (like Gravity) and a different Container and file from a different Skin (for example, the containers on the Cavalier skin).

Once you upgrade to 9.1.1 Version, when you update the web page, Evoq 9.1.1 will change the container to the default container of the Skin that is currently applied, which means that if you had Gravity skin with Cavalier Containers and files applied, once you make the first change, this new version will set the container to the Gravity default container. And as a result, there will be a visual misplacement of objects in the container/skin.

Resolution

To fix this issue, you can use one of these 2 workarounds:

Rework the whole page, combining theme and skin to look visually better.
Make the current container contain the missing skin (in the 9.1.1. version):
1. Go to the Container folder, under Portals\_default\Containers:
2. Backup the folder contents before making any change to the files, so it is possible to revert it after the fix.
3. Select the proper container applied before the migration (in the example given, it would be the Cavalier container). Let’s say in this case the container name was Title_h2.ascx.
4. Copy the file (Title_h2.ascx) from the Cavalier containers folder and paste it inside the Gravity skin’s container folder. In this case, as we used Gravity as the main skin, then we will have something like the image below:
5. Confirm replacement in the destination if this dialog box is displayed.
6. Go to Persona Bar > Manage > Themes:
7. Click in the Main Skin (Gravity), and when you customize the Containers, you will find the container that you copied from the other skin (the one that you used to have before this update).
8. Click on it and your Page will take the exact shape from the previous version, when you save the changes.