How to deal with 500.19 0x800700c1 error.

Currently this issue has been observed only with Windows Server Update Services (WSUS). Please let us know if you have this issue without WSUS

Apparently, DynamicCompressionModule and StaticCompressionModule are installed by WSUS globally and propagate to other web sites. They try to load in every Application Pool, regardless of whether it is 64-bit or 32-bit, resulting in HTTP Error 500.19 - Error Code 0x800700c1 for sites running in 32-bit mode.

Check in the "C:\Windows\System32\inetsrv\config\applicationHost.config" for the following entries within the <modules>:

<add name="DynamicCompressionModule" lockItem="true" /> <add name="StaticCompressionModule" lockItem="true" />

These entries can also be found in <globalModules> sections, but the changes are required in the <modules> section.

We would like to have those modules being loaded only for 64-bit applications. As TFS4JIRA is 32 bit we need to rule out those modules. You can do that by adding a preCondition="bitness64"

<add name="DynamicCompressionModule" lockItem="true" preCondition="bitness64" /> <add name="StaticCompressionModule" lockItem="true" preCondition="bitness64" />

After doing that restart IIS. You can do that by opening command prompt as administrator and typing iisreset.