User is trying to open the details of a project, but cannot find the tabs (General, Performance, Transactions, etc) on the screen. The same thing happens when opening the detail view in other screens.
This can happen if your browser or screen resolution is too small for all the tabs to fit. In that case, Core collapses these tabs into a drop-down on the top-right of the screen. You can either access the tabs from this drop-down or you can try zooming out on the browser so that there is enough room for the tabs to return to the expanded state.