[solved] Need help with float

const float val = 566f/10f;

public void Setup () 
{
  Console.WriteLine ("Value={0:F2}",val);
}

const float val = 56.6f;

Error CS0589 in line 2 column 23, Internal compiler error during parsingSystem.FormatException: Input string was not in the correct format
Error in line -11 column 0, at System.Double.Parse (System.String s, NumberStyles style, IFormatProvider provider) [0x00000] in :0
Error in line -11 column 0, at System.Single.Parse (System.String s, NumberStyles style, IFormatProvider provider) [0x00000] in :0
Error in line -11 column 0, at Mono.CSharp.Tokenizer.adjust_real (TypeCode t, Location loc) [0x00000] in :0
Error in line -11 column 0, at Mono.CSharp.Tokenizer.is_number (Int32 c, Boolean dotLead) [0x00000] in :0
Error in line -11 column 0, at Mono.CSharp.Tokenizer.xtoken () [0x00000] in :0
Error in line -11 column 0, at Mono.CSharp.Tokenizer.token () [0x00000] in :0
Error in line -11 column 0, at Mono.CSharp.CSharpParser.yyparse (yyInput yyLex) [0x00000] in :0
Error in line -11 column 0, at Mono.CSharp.CSharpParser.parse () [0x00000] in :0
Program disabled, fix errors first.

const float val = 56.6f;

$ locale -a
C
C.UTF-8
POSIX
en_GB.utf8
fr_FR.utf8
 $ locale
LANG=fr_FR.UTF-8
LANGUAGE=
LC_CTYPE="fr_FR.UTF-8"
LC_NUMERIC="fr_FR.UTF-8"
LC_TIME="fr_FR.UTF-8"
LC_COLLATE="fr_FR.UTF-8"
LC_MONETARY="fr_FR.UTF-8"
LC_MESSAGES="fr_FR.UTF-8"
LC_PAPER="fr_FR.UTF-8"
LC_NAME="fr_FR.UTF-8"
LC_ADDRESS="fr_FR.UTF-8"
LC_TELEPHONE="fr_FR.UTF-8"
LC_MEASUREMENT="fr_FR.UTF-8"
LC_IDENTIFICATION="fr_FR.UTF-8"
LC_ALL=

$ export LANG="en_GB.utf8"
$ locale
LANG=en_GB.utf8
LANGUAGE=
LC_CTYPE="en_GB.utf8"
LC_NUMERIC="en_GB.utf8"
LC_TIME="en_GB.utf8"
LC_COLLATE="en_GB.utf8"
LC_MONETARY="en_GB.utf8"
LC_MESSAGES="en_GB.utf8"
LC_PAPER="en_GB.utf8"
LC_NAME="en_GB.utf8"
LC_ADDRESS="en_GB.utf8"
LC_TELEPHONE="en_GB.utf8"
LC_MEASUREMENT="en_GB.utf8"
LC_IDENTIFICATION="en_GB.utf8"
LC_ALL=

const float val = 56.6f;

public void Setup () 
{
  Console.WriteLine ("Value={0:F2}",val);
}

Value=56.60