lineAddProvider fails with 0x80000048(LINEERR_OPERATIONFAILED) in Windows 8.1

[Rohan Shetty]

Hi,

I have the following code which adds the TSP into the "Phone/modem Options"

HMODULE hDLL = LoadLibrary("TAPI32.DLL");

if (hDLL)
{
LPFNADDPROVIDER pFunction = (LPFNADDPROVIDER)GetProcAddress(hDLL, "lineAddProvider");
if (pFunction)
{
DWORD dwPermanentProviderID;

//char lpszUIDLLName[] = "c:\\windows\\system32\\teles.tsp";
char lpszUIDLLName[] = "teles.tsp";


long lResult = (pFunction)(lpszUIDLLName, NULL, &dwPermanentProviderID);
printf("result=%x \r\n", lResult);
}
FreeLibrary(hDLL);
}

This works fine in most of the operating systems(XP, Win7, Vista).

But on Windows 8.1, I always get the error 0x80000048(LINEERR_OPERATIONFAILED) for the lineAddProvider.

I have also tried giving the complete path "c:\\windows\\system32\\teles.tsp", even this gives the same error.

Notes:
- It works fine when I do this from the user interface(i.e Phone and Modem Options -> Advanced -> Add).

Any help is appreciated.

Regards,
Rohan

[Rohan Shetty]

Some more information regarding this problem
- I could reproduce this every time in windows 8.1 64 bit
- I have also tried with TB20.exe, I do get the same problem
- I have tried to lineAddProvider for one of the standard tsp(i.e Microsoft HID phone TSP - hidphone.tsp) which comes as default TSP.I do get the same error.

Note: Everything works fine when I do this from "Phone and Modem Options" -> "Advanced" -> "Add"

[Andreas Marschall [exMVP TAPI]]

Am Freitag, 25. April 2014 11:10:53 UTC+2 schrieb Rohan Shetty:
> - I could reproduce this every time in windows 8.1 64 bit
> - I have also tried with TB20.exe, I do get the same problem

> Note: Everything works fine when I do this from "Phone and Modem Options" -> "Advanced" -> "Add"

Rohan,
I can confirm this on a MS Surface Pro1 with Win8.1x64.

I tested this with siptapi.tsp and remotesp.tsp.
Both could successfully be added from Telephon.CPL but not via lineAddProvider() from TB20.exe
I noticed that you get always LINEERR_OPERATIONFAILED no matter what you specify for szProviderFilename.

Am pretty sure that lineAddProvider() worked ok on the same machine before upgrading it from Win8.0x64 to Win8.1x64 (German version).

I suggest reporting this issue directly to MS.

--
Best Regards
Andreas Marschall
Microsoft MVP for TAPI / Windows SDK / Visual C++ 2003-2008
TAPI / TSP Developer and Tester
My TAPI and TSPI FAQ:
http://www.I-B-A-M.de/Andreas_Marschall's_TAPI_and_TSPI_FAQ.htm
My Toto® Tools (a collection of free, mostly TAPI related tools):
http://www.I-B-A-M.de/Andreas_Marschall's_Toto_Tools.htm
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[Rohan Shetty]

Thanks Andreas.