module_encoding

A module is not UTF-8 or starts with a byte-order mark.

A module's bytes are not valid UTF-8, or the file starts with a UTF-8 byte-order mark (BOM). Modules must be plain UTF-8 text with no BOM.

Why it happens

Some editors on Windows save files as UTF-16, as a legacy code page (such as Windows-1252), or as "UTF-8 with BOM". Non-ASCII characters in strings or comments then turn into invalid bytes.

Wrong

src/main.js   saved as "UTF-8 with BOM" (starts with EF BB BF)

Right

src/main.js   saved as "UTF-8" (no BOM)

Re-save the file as UTF-8 without a BOM; most editors show the encoding in the status bar.

See also

• Project structure & imports

• module_syntax