Symptoms

JIRA is behind IIS and when trying to access JIRA URLs that contain a plus symbol in it, the page doesn't bring JIRA content. Instead, to returns the message "The request filtering module is configured to deny a request that contains a double escape sequence".

The following appears in the screen:

Cause

By default, IIS prohibits any URL that contains a '+' character in the URL from being served.

Resolution

Set IIS to allow double escaping for JIRA site. It can be done in three different ways:

• Directly through IIS console as instructed in this documentation;

• Or directly modifying the web.config file of the IIS Site, inside the <system.webServer> tag, add the following:

  <security>
  <requestFiltering allowDoubleEscaping="true" />
  </security>

• Or via command line in the IIS server:

  %windir%\system32\inetsrv\appcmd set config "<JIRA_site_name_in_IIS>" -section:system.webServer/security/requestfiltering -allowDoubleEscaping:true

  It may need to restart JIRA site in IIS.