Hello,
Please provide a screenshot of the error. Lightshot Screenshot tool https://app.prntscr.com/en/index.html makes screenshots and generates links then you can provide links of screenshots here via Private Content area – https://prnt.sc/u7vwsg
Note that one standard license is valid only for 1 project (1 live and 1 staging websites of the same project). Running multiple projects on a single license is a copyright violation – https://themeforest.net/licenses/terms/regular
If you are using the latest WordPress version, to be able to activate the theme, you need to use the latest XStore version – https://www.8theme.com/documentation/xstore/theme-installation/theme-update/
Regards