IBM Connections – problem displaying thumbnails for Office files

A few weeks ago we migrated the environment of a customer from Connections 4.0 to 5.0 CR2.
In that step we also integrated IBM Docs (Viewer and Conversion parts) as a new feature to the setup. After successful data migration a few days later we noticed some problems with thumbnails not being display in the “grid view” of Files. We first noticed this on Powerpoint files.


Analyzing the problem

Taking the “Troubleshooting media views and thumbnail generation” documentation into consideration, we first tried to manually generate the thumbnails for all files:


After about 35 minutes the task was finished, but we were disappointed – the thumbnails for the Powerpoint files were still not being displayed.
We went ahead and did some deeper analysis of the affected files. As it shows it would only happen to “.ppt” files. The new “.pptx” format would work fine.
In addition, if you wanted to access these “.ppt” files via the Docs Viewer, you would get different error messages in the browser: “Not authorized to access the file” was just one of them.

Looking at the SystemOut.log we got a more detailed error message:

ViewDocServle W CLFAF402W: Unsupported MIME type.The MIME type of FILENAME.ppt is application/mspowerpoint

There was the root of the problem. IBM Docs is not able to access these files because of an incorrect MIME type.
The next step was to figure out the correct MIME type needed. This information can be retrieved from the “mime-files-config.xml” file in the LotusConnections-config folder:

<mapping mediaType="presentation" mimeType="application/">
<extension openFromWeb="true">pps</extension>
<extension openFromWeb="true">ppt</extension>

Using this information we can update the problematic files in the database:

db2 "update FILES.MEDIA set MIME_TYPE='application/' where FILE_EXTENSION='.ppt' and MIME_TYPE='application/mspowerpoint'"

After this, we once again executed the wsadmin task “FilesThumbnailService.generateForAllFiles()” and a few minutes later we would be able to view the thumbnails in the files grid view of Connections. The access via Docs Viewer would also work as it should.

Source of the Problem

The interesting part is, that this problem would only appear on files which we migrated from the old 4.0 environment. If you would upload a new .ppt file to Connections this would not happen.
So there must have been a change between 4.0 and 5.0 CR2 how MIME types for office files are handled.

We also noticed this problem for Excel files after going through the SystemOut.log and searching for the “Unsupported MIME type” message. You can fix this just in the same approach.
Word files seem not to be changed. The MIME type in the mime-files-config.xml is still set to “application/msword”.

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