# PDF macro failed to generate the thumbnail image

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Platform Notice: Server and Data Center Only - This article only applies to Atlassian products on the server and data center platforms.

# Summary

Scanned PDF document that consists a single embedded image won't be displayed correctly in PDF macro on the Confluence page. However, PDF preview works as expected.

• Scanned PDF

# Diagnosis

The following message appears in the atlassian-confluence.log, when the PDF file view macro attempted to generate the thumbnail image and failed:

atlassian-confluence.log
WARN [DefaultSlideCacheManager:thread-1] [conversion.convert.image.MemoryAwarePDFRenderer] drawImage Image of size 1656*2339 px dropped for memory protection
-- referer: http://localhost:8090/confluence/display/ct/testpage | url: /confluence/plugins/servlet/pptslide | traceId: a6c6cd1339882b25 | userName: admin

# Cause

Image rendering takes an amount of memory and sometimes make the Confluence instance crash. To prevent the problem, Confluence then applied memory protection by design.

# Workarounds

### Option One (Preferred)

Convert the scanned documents into JPEG or PNG format instead of PDF.

### Option Two

Please do take note that by performing this workaround and disabling the memory guard, you may hit into OutOfMemoryErrors if a high-resolution image is embedded in a PDF.

#### In Linux

1. Open the setevn.sh from the Confluence installation folder

setenv.sh
CATALINA_OPTS="-Dpdf.render.memory.guard.disabled=true \${CATALINA_OPTS}"
3. Restart Confluence
4. Navigate to the page, delete the original attachment to clear the corrupted thumbnail
5. Re-attach it to the page
6. Add the PDF macro to the page

#### In Windows, with Confluence running as a service

1. Identify the name of the service that Confluence is installed as in Windows (Go to Control Panel > Administrative Tools > Services

We are expecting to see a service name like this Confluence251017164028

2. Open the command window (Choose Start > cmd.exe)
3. cd to the bin directory of your Confluence installation folder and run the following command:

tomcat9w.exe //ES//%service_name%
4. Click on the Java tab to see the list of current start-up options
5. In the Java Options box, add:

-Dpdf.render.memory.guard.disabled=true
6. Restart the service

For more details, please refer to Configuring System Properties - Windows service

7. Navigate to the page, delete the original attachment to clear the corrupted thumbnail
8. Re-attach it to the page
9. Add the PDF macro to the page