If you are using unicorn with your Sitecore solution, and trying to install any module or any sitecore package. Then there may be some chances to get below error as
"You cannot have a sparse serialized tree. You may need to serialize this item's parents"
If yes, then just disable configuration file as Unicorn.DataProvider.config which you can get inside App_Config directory.
now install module/package. And once installation done please must follow below best practices
1. once installation done, enable Unicorn.DataProvider.config again
2. If using unicorn for Sitecore item sync, then avoid to install sitecore packages.
Please comment, if issue still persist.
