Android - Files that are not valid utf8 / utf-8 are silently hidden

[clach04]

Example scenario, existing text file gets edited on Windows and add Unicode quotation marks in a cp1252 environment (Western Europe) in a text editor like Scite, vim, etc.:

“hello”

E.g. copy/pasting from web site, email, Microsoft Word, etc.

File appears to vanish from phone on next sync.

Idea show replacement characters instead for problem bytes, 'REPLACEMENT CHARACTER' (U+FFFD)