Canon 90D will not focus nor take pictures

[gunnycc]

I was at an air show and was using my D90 and was on Manual mode. I was using a 70-200iii along with the extender. I was shooting in high speed. This was the second day doing this. The Blue Angels were flying and I just kept clicking. The camera then said busy and stayed like that for a long time. I had to turn off take memory card our remove battery, then re-install and turn on. It would then work for about 2 or 3 pictures then it wouldn't say busy, it would just not focus and not take a picture. I had to do this several times, then tried it with manual mode, same thing; then tried, auto shooting mode and manual, same 2 or 3 pictures then not focus and not take pictures. Having a lens belt I quickly removed extender, same issue, switched lenses, same issue.Any ideas??? I would hate to be at another time sensitive performance and not be able to take pictures.

[gunnycc]

Besides incredible videos with these canon lenses, I believe shooting in large RAW gives me the advantage to crop and enlarge. In this case I can almost identify the tattoos of the Seal Team Parachutist.. I am amazed by the tech. I shoot manual now about 90% of the time and am getting a bit quicker than I use to ( I do Real Estate Photography, but love just about any kind of photography, especially what I call "Opportunity Photography"!  Alas, this does fill up my memory cards...