Problem

After upgrading to JIRA 7.x, error below can be seen in all existing issues with attachments, or after trying to attach any files but failed.

The following appears in the atlassian-jira.log

2016-05-04 20:47:48,617 http-nio-8080-exec-5 ERROR admin 1247x814x1 1uvyb4z 0:0:0:0:0:0:0:1 /browse/SSPA-2 [c.a.j.web.component.ModuleWebComponentImpl] An exception occured while rendering the web panel: com.atlassian.jira.jira-view-issue-plugin:attachmentmodule (null)
java.lang.NumberFormatException: null
	at java.lang.Integer.parseInt(Unknown Source)
	at java.lang.Integer.parseInt(Unknown Source)
	at com.atlassian.jira.issue.thumbnail.DefaultThumbnailManager.doGetThumbnail(DefaultThumbnailManager.java:172)
	at com.atlassian.jira.issue.thumbnail.DefaultThumbnailManager.getThumbnail(DefaultThumbnailManager.java:129)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

Diagnosis

Diagnostic Steps

• Check if the application is an upgraded version from JIRA 6.x or earlier and there's a modified jpm.xml.(located in the <jira-application-dir>/WEB-INF/classes subdirectory of the JIRA Installation Directory.

      ___ Modifications ___________________________
      
           Modified Files                                : jira-application.properties, jpm.xml

• In jpm.xml, <key>jira.thumbnails.scaling.factor</key> is not found.

Cause

The jpm.xml file, which is placed at $JIRA_INSTALL/atlassian-jira/WEB-INF/classes folder, has been modified. This can be diagnosed upon checking the startup log entries on atlassian-jira.log or catalina.out.

<key>jira.thumbnails.scaling.factor</key> does not exist in jpm.xml in earlier version of JIRA, if the jpm.xml from earlier version of JIRA is used in JIRA 7.x, there will be problem rendering the attachmentmodule and attaching new files.

Workaround

• Add the property below to the jpm.xml and restart JIRA.

          <property>
              <key>jira.thumbnails.scaling.factor</key>
              <default-value>4</default-value>
              <type>uint</type>
              <admin-editable>false</admin-editable>
              <sysadmin-editable>true</sysadmin-editable>
              <requires-restart>false</requires-restart>
          </property>

Resolution

Replace the modified jpm.xml with the original file corresponding to the JIRA version.