FCX insert frame sequence from png?

Question

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A few seconds of video saved as an Image Sequence. Processed in Photoshop now I want to insert a sequence of frames in FCP X. I used to do this. I create a project in Motion, specify the first frame, and now the Image Sequence checkbox is not active.
Tried:
- resaved one of the frames in tiif (didn't help);
- once again saved a part of the video as an Image Sequence processed in Photoshop (one frame) opened through Motion as an Image Sequence everything works;
Solutions:
- once again process 100 frames in Photoshop (this is a complete ***);
- paste in FCP X the whole sequence of frames and change the default duration from 10 sec to 1 frame. In the seven I did
it how to do it in FCP X (if not handles each png)?
Why might the Image Sequence not be active?
Which option is better through Image Sequence or insert all png on the timeline as a separate frame?