The Android Studio work window (bar) does not appear.

I'm currently using Android Studio 3.0, but after the update, the list of tasks tabs in the open file has disappeared, maybe something has changed. It's so hard to move from project to project because it's uncomfortable. I need your help. I tried reinstalling it, but it's the sameyo

You can't see the tabs that are supposed to be at the bottom of the toolbar in this picture.

I tried it basically, but it doesn't look like a picture, and I've tried all the other projects, but it's because I'm incompetent.