come a cropper

come a cropper {UK} (fall over || fail at some venture; make a mistake which has serious consequences for one) — свалиться, упасть (и ушибиться) {букв. упасть с лошади вниз головой}; || потерпеть крах (фиаско, неудачу), провалиться с треском, сесть в лужу, сесть в калошу; облажаться|| вылететь в трубу
Also come a howler AND come a mucker

Example 1: She came a cropper while coming down the steps and hurt her backside.

Example 2: He'll come a cropper sooner or later. Types like that always do. I just hope I'm still around to see it. I might write a book about it. I've been taking notes. (David Rosner, What's Done is Done, 1991)

Example 3: If outside buyers and suppliers lose faith, the company can come a cropper overnight, regardless of how valuable its goods and services ultimately may prove.

Example 4: Mr. Brown did not have enough money to put into his business and it soon came a cropper.

see also
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come a cropper (букв. упасть с лошади вниз головой)