Locate "Barra de navegació"->"Término de búsqueda o dirección" and browse "http://www.columbia.edu/~fdc/utf8/" website - results in:
Exception UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 73: ordinal not in range(128)

If i correct the word navegació to navegación, there's no UnicodeDecodeError

Locate "URL \u307e\u305f\u306f\u691c\u7d22\u8a9e\u53e5\u3092\u5165\u529b\u3057\u307e\u3059"->"URL \u307e\u305f\u306f\u691c\u7d22\u8a9e\u53e5\u3092\u5165\u529b\u3057\u307e\u3059" and browse "http://www.google.com" website throws the same error. if the first "URL \u307e\u305f\u306f\u691c\u7d22\u8a9e\u53e5\u3092\u5165\u529b\u3057\u307e\u3059" is replaced with "\u30ca\u30d3\u30b2\u30fc\u30b7\u30e7\u30f3\u30c4\u30fc\u30eb\u30d0\u30fc" that is actually expected, there's no error.

Locate "\u179a\u1794\u17b6\u179a\u200b\u17a7\u1794\u1780\u179a\u178e\u17cd\u200b\u179a\u17bb\u1780\u179a\u1780\u200b"->"\u179f\u17d2\u179c\u17c2\u1784\u179a\u1780 \u17ac\u200b\u1794\u1789\u17d2\u1785\u17bc\u179b\u200b\u17a2\u17b6\u179f\u1799\u178a\u17d2\u178b\u17b6\u1793" and browse "http://www.google.com" website 

versus 

Locate "\u179a\u1794\u17b6\u179a\u200b\u1798\u17c9\u17ba\u1793\u17bb\u1799"->"\u179f\u17d2\u179c\u17c2\u1784\u179a\u1780 \u17ac\u200b\u1794\u1789\u17d2\u1785\u17bc\u179b\u200b\u17a2\u17b6\u179f\u1799\u178a\u17d2\u178b\u17b6\u1793" and browse "http://www.columbia.edu/~fdc/utf8/" website - this is km_KH.utf8 locale. msg313133 is ja_JP.utf8 locale

it looks like python unicode decode cannot compare strings well in these locales.

The problem here is that the error message is trying to write to an output device using ASCII.  If there is no error, there is no error message print attempt. The error message, when written to an ASCII device, needs to be escaped.

You don't show the code, so it is hard to say more about the issue.

Jiri, if you are still having this problem in 3.9+, and Glenn's suggestion to escape the error is not helpful, please create a new issue and include code to reproduce it.

Python 2.7 is no longer maintained.