Lost frame in 120 fps

when I film with my bmpcc 4k in 120 fps, I have an alert message because frames are lost. I can check this in my timeline because there are frames replaced by red squares. How to solve this problem?
Thanks for your answer

Only use media that is tested by BM. If you already do, check your cables.
Or do you mean when it's already shot and you can't reshoot? There is a complicated trick, by which you can save such recordings to some degree if the missing frames are only few.

Merci pour votre réponse.
Bien cordialement
Philippe

How to solve this problem?

Test all media before you shoot with it.

(Find out what it's limits are.)

Seconded, and set the camera to stop when frames are dropped. It'll make it more obvious.