Using a map with either a text or csv file, when I preview the map I see extra characters at the beginning of the first column name. If I open the file it looks completely normal with no extra characters.
These are hidden characters in a UTF-8-BOM file. The UTF-8-BOM is a sequence of bytes at the start of a text stream (0xEF, 0xBB, 0xBF) that allows the reader to more reliably guess a file as being encoded in UTF-8.
Normally, the BOM is used to signal the endianness of an encoding, but since endianness is irrelevant to UTF-8, the BOM is unnecessary.
According to the Unicode standard section 2.6, the use of a BOM is neither required nor recommended for UTF-8, but may be encountered in contexts where UTF-8 data is converted from other encoding forms that use a BOM or where the BOM is used as a UTF-8 signature.
SmartConnect will not work with UTF-8-BOM files, they need to be converted to standard UTF-8 encoding.