Roto Brush Tool Section is not showing

I try it all the solutions commented but none worked, if anyone have the same problem in 2024 (24.3.0 version), just restart the computer and it's done! 

Try switching between these toggle... Maybe this might help? 🙂

This seemed to work for me:
1. Turn off the "Roto Brush & Refine Edge" fx toggle in the Effect Controls panel of the layer you're rotoscoping.

2. With the "Roto Brush Tool" selected, click and drag on the layer. (A new instance of "Roto Brush & Refine Edge" will appear in the Effect Controls panel) - The pink selection line appears again.

3. Undo/Delete the new effect.

4. Turn on the previous "Roto" effect. - The pink selection line should appear again.

I solve the same problem by:

1. Exporting the original video in Premiere as a new video vlip, using the same framerate and size as in the end sequence were I am going to keep working.

2. Importing the new video again in the timeline.

3. I opened the clip again in my Premiere sequence and the I substitude it as an After Effects Composition (Right click on the clip in the timeline, and then look into the options in the menu).

It seems that the video clip giving me a hard time had some problems with the frame rate ore some missing frames.

I solve the same problem by 1. exporting the original video in Premiere ass a new VideoClip. 2. Reimporting the Video in the Timeline 3. I opened the clip again as a After Effects Composition (Right Click on the clip in the Timeline, and look then the options). It seems that the Clip had some problem with the FrameRate ore some missing Frames.

What you're encountering appears to be a bug.  A couple of suggestions.
1. Try changing toggle settings (switch between alpha, alpha boundary, etc.).  That might force a redraw of the layer viewer to correctly display your line segmentation.
2. Try moving the CTI to a new frame within the span.  

We just this week released to the public a new version of AE (17.5) that includes Roto Brush 2.  It’s a major overhaul to the rotoscoping experience in AE, includes many bug fixes, UI improvements, and has faster and better segmentation results. 

For reference, here’s a link to the most up to date help file on Roto Brush and Refine Matte workflow:
https://helpx.adobe.com/in/after-effects/using/roto-brush-refine-matte.html

Thanks

Had you been able to solve it?? I'm having the exact same problem which renders the rotobrush almost unusable. There's no answers from this in any part. If adobe continue having this bugs I'll end up moving to other softwares