Confluence UI shows garbled or corrupt text on CAPTCHA, macros and/or diagrams due to missing fonts
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
Summary
Problem
Following a Confluence upgrade running on an older Linux distribution, you might encounter a problem where certain system text in the application will appear to be garbled and look like symbols instead of regular alphanumeric letters.
You will not see any errors in the logs relating to the issue, however, you might see warnings about fonts in general.
This has been observed in the following areas of Confluence
CAPTCHA
Macro headers
Inline charts and diagrams
Imported Microsoft Word Documents
Diagnosis
In order to identify whether you are affected by this issue, you will need to answer the below questions:
Did you upgrade Confluence Server recently to a new version?
Are you running an older version of a Linux distribution that is behind current release cycle (possibly more than 3+ years old)?
Cause
If you answered yes to both of the above questions, you might be missing fonts on the OS level that more recent versions of Confluence depend on to render pages properly. Bug report for reference: CONFSERVER-54067 - Confluence UI shows garbled or corrupt text on CAPTCHA, macros and/or diagrams due to missing fonts in Linux
Solution
Resolution
Resolution 1
Uninstall lyx-fonts package (Lyx/MathML fonts - A collection of Math symbol fonts for lyx)
Resolution 2
You will need to check and install the following font packages. You can use any package manager you like. For this example, we will be using yum
1
2
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yum install ghostscript
yum install dejavu-fonts-common
yum install dejavu-sans-fonts
yum install dejavu-sans-mono-fonts
yum install motifSome versions of ghostscript packages can be affected by security vulnerability CVE-2018-16509 discovered in September 2018.
for more details see
In order for Confluence to pick up the changes, please apply the below steps:
Stop Confluence
Rebuild the font cache by using the following command:
1fc-cache -sClear the How to clear the apps (plugins) cache in Confluence Data Center.
Perform a How to Rebuild the Content Indexes From Scratch on Unclustered Confluence.
Start Confluence.
Clear your browser cache and verify Confluence is presenting the text properly.
If you still see garbled text, try rebooting the server, then check again.
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