Hi Mirek,

I have now tested 9105 on Windows 8.1 Professional x64 with the following results:

2. It still can't find the installed Visual studio 2015 community edition. Is this expected?

		vc = df.ScanForDir("/vc", "", "bin/link.exe;bin/cl.exe;bin/mspdb140.dll", "bin/1033");
		bin = df.ScanForDir(x64 ? "bin/x64" : "bin/x86", "/windows kits/", "makecat.exe;accevent.exe", "");
		inc = df.ScanForDir("", "/windows kits/", "um/adhoc.h", "um;ucrt;shared");
		lib = df.ScanForDir("", "/windows kits/", "um/x86/kernel32.lib", "um;ucrt");

DUMP(vc); DUMP(bin); DUMP(inc); DUMP(lib); // <<==== THIS
		
		if(vc.GetCount() * bin.GetCount() * inc.GetCount() * lib.GetCount()) {
			bins.At(0) = vc + (x64 ? "/bin/amd64" : "/bin");
			bins.At(1) = bin;
			String& sslbin = bins.At(2);

3. MINGW Debug compiles UWord correctly and the resulting executable works.

4. MINGW Size compiles UWord correctly and the resulting executable works.

5. MINGW Optimal compiles UWord but the resulting executable crashes. It requires dropping the speed optimization flag from O3 to O2 in order to make it work.

6. MINGW Speed compiles UWord but the resulting executable crashes. It requires dropping the speed optimization flag from O3 to O2 in order to make it work.

7. MINGWx64 Debug compiles UWord correctly and the resulting executable works.

8. MINGWx64 Size compiles UWord but the resulting executable crashes. (Switching from Os to e.g. O0 in size optimization flags fixes the executable.)

9. MINGWx64 Optimal compiles UWord but the resulting executable crashes. (Switching from Os to O0, O1, O2 or O3 in size optimization flags fixes the executable.)

10. MINGWx64 Speed compiles UWord correctly and the resulting executable works.

Best regards,

Tom