The wrong character is displayed when a smart apostrophe (') or quote characters (") are typed.
Smart quotes (also known as curly quotes) are considered more formal or correct than the straight apostrophe (') and straight quote or inches character (") that reside on the key to the right of the semicolon on the keyboard.
Sometimes a user may have placed the "wrong" character has been placed in one of the slots designated for the curly quotes or apostrophe characters.
Sometimes a user has put a glyph in the straight apostrophe or straight double quote slot, but their app is automatically trying to substitute the “smart” version... which the user has not put in the font.
Either turn the "Smart Quotes" preference off in the application, or do not place incorrect glyphs in these slots, or make sure you have also created the correct smart quote characters.
Quote marks or apostrophes do not display in application software.
The "Smart Quotes" preference has been turned off in the application software.
In the majority of cases, this is solved by turning on the "Smart Quotes" option in the application software. Future conflicts may be avoided by pasting the preferred (straight or curly) type of quotes and apostrophes into all slots where these characters are assigned. Once that has been done, only the desired characters can be displayed, regardless of the settings for the application's preferences. See the appropriate table in the manual to determine which slots contain the characters for a specific encoding vector.