Not enough info (see below).
Best bet is to call Davis.
If you said what WeatherLink did without the WU stuff, that would help. Also, what version of WU module. And captured the details of the error, rather than just the summary display, we might have a clue. But probably not.
Telling us whether it fails without the WU stuff would at least cut the problem in half.
Oh, and what operating system?
WeatherLink freezes 2-3 minutes after opening. I removed the
http://wiki.wunderground.com/index.php/PWS_-_WeatherLink (WuiWlink_1.dll) and WeatherLink didn't freeze. I re installed the module and WeatherLink froze within a minute.
Windows 8
The complete error report when using WU
<?xml version="1.0" encoding="UTF-16"?>
<DATABASE>
<EXE NAME="WeatherLink 6.0.2.exe" FILTER="GRABMI_FILTER_PRIVACY">
<MATCHING_FILE NAME="CP210xManufacturing.dll" SIZE="94208" CHECKSUM="0xB5C83303" BIN_FILE_VERSION="3.4.0.0" BIN_PRODUCT_VERSION="3.4.0.0" PRODUCT_VERSION="3.4" FILE_DESCRIPTION="CP210x Manufacturing Interface DLL" COMPANY_NAME="Silicon Laboratories" PRODUCT_NAME="Silicon Laboratories CP210x USB to UART Bridge" FILE_VERSION="3.4" ORIGINAL_FILENAME="CP210xManufacturing.dll" INTERNAL_NAME="CP210x" LEGAL_COPYRIGHT="Copyright © 2007" VERFILEDATEHI="0x0" VERFILEDATELO="0x0" VERFILEOS="0x40004" VERFILETYPE="0x2" MODULE_TYPE="WIN32" PE_CHECKSUM="0x0" LINKER_VERSION="0x0" UPTO_BIN_FILE_VERSION="3.4.0.0" UPTO_BIN_PRODUCT_VERSION="3.4.0.0" LINK_DATE="01/24/2008 19:50:35" UPTO_LINK_DATE="01/24/2008 19:50:35" VER_LANGUAGE="English (United States) [0x409]" />
<MATCHING_FILE NAME="SiUSBXp.dll" SIZE="90112" CHECKSUM="0x2D011F54" BIN_FILE_VERSION="3.1.0.0" BIN_PRODUCT_VERSION="3.1.0.0" PRODUCT_VERSION="3.1" FILE_DESCRIPTION="SiUSBXp" COMPANY_NAME="Silicon Laboratories, Inc." PRODUCT_NAME="Silicon Laboratories USBXpress" FILE_VERSION="3.1" ORIGINAL_FILENAME="SiUSBXp.dll" INTERNAL_NAME="USBXpress" LEGAL_COPYRIGHT="Copyright © 2006" VERFILEDATEHI="0x0" VERFILEDATELO="0x0" VERFILEOS="0x40004" VERFILETYPE="0x2" MODULE_TYPE="WIN32" PE_CHECKSUM="0x0" LINKER_VERSION="0x0" UPTO_BIN_FILE_VERSION="3.1.0.0" UPTO_BIN_PRODUCT_VERSION="3.1.0.0" LINK_DATE="02/12/2007 15:45:48" UPTO_LINK_DATE="02/12/2007 15:45:48" VER_LANGUAGE="English (United States) [0x409]" />
<MATCHING_FILE NAME="WeatherLink 6.0.2.exe" SIZE="2279936" CHECKSUM="0x6E161531" BIN_FILE_VERSION="5.9.0.0" BIN_PRODUCT_VERSION="5.9.0.0" PRODUCT_VERSION="5, 9, 2, 0" FILE_DESCRIPTION="WeatherLink" COMPANY_NAME="Davis Instuments Corp." PRODUCT_NAME="WeatherLink" FILE_VERSION="5, 9, 2, 0" ORIGINAL_FILENAME="WeatherLink 5.9.2.exe" INTERNAL_NAME="WeatherLink 5.9.2" LEGAL_COPYRIGHT="Copyright © 2001-2009" VERFILEDATEHI="0x0" VERFILEDATELO="0x0" VERFILEOS="0x40004" VERFILETYPE="0x1" MODULE_TYPE="WIN32" PE_CHECKSUM="0x2338E4" LINKER_VERSION="0x60000" UPTO_BIN_FILE_VERSION="5.9.0.0" UPTO_BIN_PRODUCT_VERSION="5.9.0.0" LINK_DATE="08/27/2012 21:34:03" UPTO_LINK_DATE="08/27/2012 21:34:03" VER_LANGUAGE="English (United States) [0x409]" />
<MATCHING_FILE NAME="Expansion_Modules\WuiWlink_1.dll" SIZE="638976" CHECKSUM="0x2D023B8F" MODULE_TYPE="WIN32" PE_CHECKSUM="0x0" LINKER_VERSION="0x0" LINK_DATE="12/27/2007 18:12:18" UPTO_LINK_DATE="12/27/2007 18:12:18" />
<MATCHING_FILE NAME="Support\Drivers\Direct_USB_Drivers_Win_X\USBXpressInstaller.exe" SIZE="298632" CHECKSUM="0xA97DC956" BIN_FILE_VERSION="2.0.0.0" BIN_PRODUCT_VERSION="2.0.0.0" PRODUCT_VERSION="2.0" FILE_DESCRIPTION="Driver Installation Utility" COMPANY_NAME="Silicon Laboratories, Inc." PRODUCT_NAME="DriverInstaller Application" FILE_VERSION="2.0" ORIGINAL_FILENAME="DriverInstaller.EXE" INTERNAL_NAME="DriverInstaller" LEGAL_COPYRIGHT="Copyright (C) 2007" VERFILEDATEHI="0x0" VERFILEDATELO="0x0" VERFILEOS="0x4" VERFILETYPE="0x1" MODULE_TYPE="WIN32" PE_CHECKSUM="0x4AF11" LINKER_VERSION="0x0" UPTO_BIN_FILE_VERSION="2.0.0.0" UPTO_BIN_PRODUCT_VERSION="2.0.0.0" LINK_DATE="03/01/2007 17:47:47" UP...