For some months dsss.exe and implib.exe worked correctly on my machine. Now
one of other programs has updated registry  settings, I guess, and as a result
when using dsss I got
'4invalid UTF-8 sequence',
 when using implib with the arguments string
"implib/system A.lib A.dll "
there is the output:
" IMPLIB: error IM4601: unrecognized option '/system'; option ignored ";
though, when using dmd itself everything is strangely  OK.
The question is simple:
how to restore now all the previous (good) settings on Windows XP Professional
(32 bits)? There might be an inner format changed,
since even text converted with Notepad++ into UTF-8
seems to be not good...

I have to add the following to my post:

In Phobos for dmd version 1 there is only one
obvious source of this exception. Namely, it is
function 'decode' in the std.utf module.
Here is its listing:

/***************
 * Decodes and returns character starting at s[idx]. idx is advanced past the
 * decoded character. If the character is not well formed, a UtfException is
 * thrown and idx remains unchanged.
 */

dchar decode(char[] s, inout size_t idx)
    in
    {
	assert(idx >= 0 && idx < s.length);
    }
    out (result)
    {
	assert(isValidDchar(result));
    }
    body
    {
	size_t len = s.length;
	dchar V;
	size_t i = idx;
	char u = s[i];

	if (u & 0x80)
	{   uint n;
	    char u2;

	    /* The following encodings are valid, except for the 5 and 6 byte
	     * combinations:
	     *	0xxxxxxx
	     *	110xxxxx 10xxxxxx
	     *	1110xxxx 10xxxxxx 10xxxxxx
	     *	11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
	     *	111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
	     *	1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
	     */
	    for (n = 1; ; n++)
	    {
		if (n > 4)
		    goto Lerr;		// only do the first 4 of 6 encodings
		if (((u << n) & 0x80) == 0)
		{
		    if (n == 1)
			goto Lerr;
		    break;
		}
	    }

	    // Pick off (7 - n) significant bits of B from first byte of octet
	    V = cast(dchar)(u & ((1 << (7 - n)) - 1));

	    if (i + (n - 1) >= len)
		goto Lerr;			// off end of string

	    /* The following combinations are overlong, and illegal:
	     *	1100000x (10xxxxxx)
	     *	11100000 100xxxxx (10xxxxxx)
	     *	11110000 1000xxxx (10xxxxxx 10xxxxxx)
	     *	11111000 10000xxx (10xxxxxx 10xxxxxx 10xxxxxx)
	     *	11111100 100000xx (10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx)
	     */
	    u2 = s[i + 1];
	    if ((u & 0xFE) == 0xC0 ||
		(u == 0xE0 && (u2 & 0xE0) == 0x80) ||
		(u == 0xF0 && (u2 & 0xF0) == 0x80) ||
		(u == 0xF8 && (u2 & 0xF8) == 0x80) ||
		(u == 0xFC && (u2 & 0xFC) == 0x80))
		goto Lerr;			// overlong combination

	    for (uint j = 1; j != n; j++)
	    {
		u = s[i + j];
		if ((u & 0xC0) != 0x80)
		    goto Lerr;			// trailing bytes are 10xxxxxx
		V = (V << 6) | (u & 0x3F);
	    }
	    if (!isValidDchar(V))
		goto Lerr;
	    i += n;
	}
	else
	{
	    V = cast(dchar) u;
	    i++;
	}

	idx = i;
	return V;

      Lerr:
	//printf("\ndecode: idx = %d, i = %d, length = %d s = \n'%.*s'\n%x\n'%.*s'\n",
idx, i, s.length, s, s[i], s[i .. length]);
	throw new UtfException("4invalid UTF-8 sequence", i);
    }

In no other place was found text "4invalid UTF-8 sequence",
therefore, this function needs a revision.
So, I myself answered to the question that concerns the dsss behavior,
as dsss is written in D. But the strange behaviour of implib still undefined.

Vitaly Kulich Wrote:

> For some months dsss.exe and implib.exe worked correctly on my machine. Now one of other programs has updated registry  settings, I guess

Photoshop encoding fix?