Why does a fixed width block break flex layout?

Question

css

Hello! Help me to understand. There is a layout built using flex technology. Three columns, 2 fixed widths (right and left sidebar) and fluid content. Everything functions and everything works well. But when a fixed-width block appears in the content, and its width is greater than the content width, the layout breaks and horizontal scrolling appears.
Here's how layout breaks:

And here's how without this block:

Also, if you fasten a slider like this , the layout also breaks.
This is what it looks like (chrome)
https://jsbin.com/bovibeniga/edit?html,css,output

Answer 1

You would have posted the code, you never know what you made up for there.