Problem

When JIRA is behind a Microsoft-based HTTP server, like IIS. JIRA functions, like page views or attempting to create an issue link, can result in a 400 Bad Request.

Steps to Reproduce

• Setup JIRA behind IIS
• Load an issue ticket and attempt to create an issue link
• Browser will receive a 400 Bad Request

Investigation

As of JIRA 7.3.2+, we plugin assets have been added to the request URLs. For example, when attempting to create an issue link the request looks like this:

• JIRA 7.3.2+

  https://mylocaljira.com/jira/s/0d089a0b9496e6961b46a6ff0fab3577-T/-2kdf3u/73014/a14cb145fcf53a0dac96c288c8cb2f1c/df1080717d136496574968aba23f1092/_/download/contextbatch/js/jira.edit.issue,-_super,-jira.view.issue,-atl.general,-jira.rich.editor,-jira.navigator.kickass,-com.atlassian.jira.plugins.jira-development-integration-plugin:devstatus-dialog-resources-ctx,-viewissue.standalone,-jira.navigator.advanced,-jira.navigator.simple,-jira.general/batch.js?agile_global_admin_condition=true&healthcheck-resources=true&is-server-instance=true&is-system-admin=true&jag=true&jaguser=true&jira-nps-enabled=true&jira.create.linked.issue=true&locale=en-US&nps-acknowledged=true&nps-not-opted-out=true&richediton=true
  

  https://mylocaljira.com/jira/s/649b65f752be8a25102e4977ed4ad1b5-CDN/-7gc8qi/73013/b6b48b2829824b869586ac216d119363/9dd2b02e9d3fe3341364f22c6a6ff474/_/download/contextbatch/css/com.atlassian.jira.jira-issue-link-confluence-plugin:init-issuelink-confluence,com.atlassian.jira.jira-issue-link-remote-jira-plugin:init-issuelink-jira,-_super,-jira.view.issue,-com.atlassian.jira.plugins.jira-development-integration-plugin:devstatus-dialog-resources-ctx,-project.issue.navigator/batch.css?jira.create.linked.issue=true&richediton=true&user-logged-in=true

• JIRA 7.3.0

  https://mylocaljira.com/jira/s/3a8c8215538460d1de361096983a5fdb-CDN/5yyz52/73011/a14cb145fcf53a0dac96c288c8cb2f1c/d07793104d5bb382d7a5a8b494b2c59a/_/download/contextbatch/js/com.atlassian.jira.jira-issue-link-remote-jira-plugin:init-issuelink-jira,-_super,-jira.view.issue,-jira.navigator.kickass,-viewissue.standalone/batch.js?jira.create.linked.issue=true&locale=en-US&richediton=true
  

Specifically pay attention to this section of the URL:

• long_jira_url/download/contextbatch/js/<EVERYTHING_HERE>/batch.js?rest_of_url

Cause

Due to the URL length increase, we are reaching the Windows Path Limit of 260 characters. This not the IIS URL limit. More details here:

• https://msdn.microsoft.com/en-us/library/aa365247(v=vs.85).aspx#maxpath
• https://social.msdn.microsoft.com/Forums/en-US/723e6bfd-cab7-417b-b487-67f1dcfa524f/uri-path-great-than-260-characters-yeilds-bad-request?forum=netfxnetcom

Workaround

From the above articles, it is possible to modify the Windows Registry of the IIS server and increase the UrlSegmentMaxLength value to handle more characters:

1. Backup the Registry
2. With Regedit, browse to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\HTTP\Parameters
3. Find the value for UrlSegmentMaxLength (or if it doesn't exist add a DWORD value), and change it to 00001000 (this is the hex for 4096)

Powershell alternative:

Set-ItemProperty -Path HKLM:\System\CurrentControlSet\Services\HTTP\Parameters -Name UrlSegmentMaxLength -Value 4096 -type DWord

After using either method to adjust the registry (Regedit or Powershell), you must restart Windows for the changes to take effect. This will necessitate downtime, please plan a maintenance window accordingly.