If you select the encoding "Plain Text", then it is ignored and the file is saved in UTF-8 without BOM.
The compiler does not to find BOM, thinks that the encoding "Plain Text" and incorrectly interprets the code symbols.
Bug № 2.
If UTF-8 encoding, and the shape is preserved mode "Design View", then the BOM in the file is not written.
In the mode "Code", does not have this problem (BOM is written to the file).