After refreshing, all tabs are closed and cannot open new tabs.

Whenever I switched to another window/application and moved back to the Rider, rider refreshes. After that, all tabs are closed,the C# scripts' icons in the left side bar disappears, and I cannot open new tab anymore.

I can see the icons and open the c# script by clicking it, after clicking “Show all files” button. But still, the same error occurs.