Why did chrome stop launching on imac?

Question

Google Chrome

Good day! Please tell me why Google Chrome stopped running on imac.
I downloaded it from the off site, installed it at first, everything worked fine, but constantly at startup some kind of window with the application’s power of attorney appeared, apparently I accidentally ticked it and after that Chrome stopped starting, you start its icon jumps and immediately disappears.
And one more related question to mac connoisseurs. There is a hot key combination for a quick screenshot command+shift+4, but how can I edit the screenshot later? Select any area, indicate an arrow, etc. like a Yandex screenshot, something like:

Answer 1

The first question: based on my experience, it will be easier for you to remove it and reinstall it.
The second question: I use Photoshop to edit screenshots, but you can do it this way - editing screenshots mac