Hello Lokesh,
Drag a dataview and move that snippet into the dataview.
You don't want to be directly editing Marketplace module such as Atlas Core. This makes it very difficult to upgrade as when you install the latest version, you loose your changes. Instead, you should create a local copy of what you want to change in a new module. In this case, copy the Atlas Default layout to your new module and make the changes there. You can then use the App -> Tools -> Batch Update Layouts... option to change your pages to use your new layout.
For your specific problem, it looks like the SNIP_User_Session is expecting some parameters to be passed to it. Have a look in the snippet, and see what those parameters are. Then, in your layout, pass those parameters in a DataView (or List View or Template Grid depending on your requirements).
Good luck!
Lokesh, Follow below steps:
1.Click on parameter in snippet and remove that parameter.
2. If you passing any parameter in microflow MF_User_Session remove that parameter.
Check issue will resolve.