Confluence reports 'Could not initialize class com.aspose.slides'
Platform notice: Server and Data Center only. This article only applies to Atlassian products on the Server and Data Center platforms.
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
Powerpoint (.PPT or .PPTX) files attached to a Confluence page can not be previewed. Attempts to preview them will result in the error:
We can't preview this file.
You'll have to download the file to view it.The following appears in the atlassian-confluence.log
2017-05-22 14:10:08,459 ERROR [conversion-thread-2] [plugins.conversion.impl.TimeoutConversionRunnable] run Cannot convert. Execution error:
-- url: /confluence/display/TP/Page+With+Powerpoint | page: 102406 | traceId: 2df69b3bd3ecd941 | userName: *****| referer: ***** | action: viewpage
java.lang.NoClassDefFoundError: Could not initialize class com.aspose.slides.ms.pbdb106a0.p6a2feef8.q
at com.aspose.slides.ms.core.p7cce53cf.pa5e0ff62.a.do(Unknown Source)
at com.aspose.slides.ms.pbdb106a0.p6a2feef8.pa5e0ff62.q.do(Unknown Source)
at com.aspose.slides.ms.pbdb106a0.p6a2feef8.pa5e0ff62.q.do(Unknown Source)Environment
- Confluence 6.0 thru 6.6.3/6.7.2
Cause
Confluence uses a third-party library, Aspose, to preview and display PPT(X) files. Somehow, the Aspose class becomes unregistered, and cannot be found.
Resolution
Upgrade the Aspose library
Due to a critical bug, an update to the Document Conversion Plugin was released for Confluence. You can download the upgrade to the add-on from that bug:
CONFSERVER-52279 - Getting issue details... STATUS
Depending on your version of Confluence:
Download the right document-conversion-library-x.x.xx.jar
Confluence version Document Library Version 6.0 - 6.4 Document conversion 1.2.25 after 6.4
Document conversion 2.0.2
- Install the add on by file upload, as per installing plugins