AppStore's webpage has a weird title

I use Greenshot that automatically saves screenshots with window titles in their names. For example, when I was browsing App Store, I took a screenshot and it was saved like this:

However, when I tried to open this image, I get this error:

What happened?

It wasn’t hard to realize that some strange character may exist in the name, because I can open it once I pressed F2 and renamed it to something else. But what exactly was wrong with the name?

I copied the name to a text file, and showed a hex dump:

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  Offset: 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 	
00000000: 32 30 32 30 2D 30 37 2D 31 36 20 31 36 5F 31 35 2020-07-16.16_15
00000010: 5F 34 39 2D E2 80 8E 54 77 69 74 74 65 72 20 6F _49-b..Twitter.o
00000020: 6E 20 74 68 65 20 41 70 70 C2 A0 53 74 6F 72 65 n.the.AppB.Store
00000030: 2E 70 6E 67 .png

What is E2 80 8E? A Left-to-right mark in UTF-8.

What is C2 A0? A Non-breaking space in UTF-8.

OK, Apple.