Error: WinHttpAddRequestHeaders failed: 6 - WKB48624

SYMPTOMS

• SFO/CFO does not communicate with MassLynx or SFO/CFO Diagnostics tool
• Error message "WinHttpAddRequestHeaders failed: 6" or prompt "Communication Failed"
• Instrument communicates via ping and is recognized by scan in the firmware loader

ENVIRONMENT

• MassLynx
• FractionLynx
• Autopurification

CAUSE

SFO/CFO has lost its serial number and will show "Serial Number Uninitialized" in the firmware loader. This cannot be set in the diagnostic tool because of the communications error.

FIX or WORKAROUND

1. Set the instrument serial number using the firmware loader:

• Open Loader.exe.
• Select "Scan for instruments" and click Next.
• Browse to SFO/CFO instrument, right-click, and select "Set Serial Number".
• Exit the loader by using the Cancel command or the Back command. (WARNING: If you click Next it will wipe the instrument firmware.)

2. Restart the instrument and MassLynx.

3. Communications with MassLynx and the SFO Diagnostics tool should now be restored.

ADDITIONAL INFORMATION

Loader.exe can be found in the Firmware folder, located on the same HDD where your drivers are installed (e.g., C:\Program Files (x86)\Waters Instruments\Firmware).