Bitbucket Server hangs showing "Loading add-on Mirror"
Platform Notice: Data Center Only - This article only applies to Atlassian products on the Data Center platform.
Note that this KB was created for the Data Center version of the product. Data Center KBs for non-Data-Center-specific features may also work for Server versions of the product, however they have not been tested. Support for Server* products ended on February 15th 2024. If you are running a Server product, you can visit the Atlassian Server end of support announcement to review your migration options.
*Except Fisheye and Crucible
Problem
In the Bitbucket Server administration panel a message is displayed saying "Loading add-on Mirror" indefinitely when performing one of these activities:
Trying to select which projects to mirror to a Bitbucket Smart Mirror:
Trying to access the Atlassian Troubleshooting and Support Tools for a Bitbucket Smart Mirror:
Diagnosis
Environment
Bitbucket Data Center with at least one Smart Mirror configured, with that Smart Mirror running behind a reverse proxy server
Cause
The reverse proxy server is setting an HTTP response header that prevents the content rendered by the mirroring add-on from being displayed.
The user interface used to select which projects to synchronize to a Smart Mirror or to display the Atlassian Troubleshooting and Support Tools is embedded into the administration panel via an iframe. If the reverse proxy has been configured to send the X-Frame-Options header with the value SAMEORIGIN, the browser will not load any content embedded via iframes, and as a result the required user interface elements will not be displayed correctly.
For instance, Apache HTTP Server can be configured to behave in this way (i.e. set this header) with the following directive:
Header always append X-Frame-Options SAMEORIGINResolution
To resolve this problem, adjust the configuration of the load balancer so it no longer sets the X-Frame-Options header with SAMEORIGIN as its value.