JIRA emails not sent: java.lang.NumberFormatException: null

In JIRA 2.3 (possibly versions after 2.1 – need to confirm), mails do not get sent out if using a freshly created database, because the "days per week" and "hours per day" properties are null. This causes exceptions every time JIRA tries to send a mail:

java.lang.NumberFormatException: null
at java.lang.Integer.parseInt(Integer.java:394)
at java.lang.Integer.parseInt(Integer.java:476)
at com.atlassian.jira.mail.IssueMailQueueItem.getIssueContextParams(IssueMailQueueItem.java:151)

Mails will build up in the queue, and won't be flushed.

For running JIRA instances, a quick fix is to go to the Administration section, select 'Time Tracking', click 'Activate' and then (optionally) Deactivate.

The full fix is as follows:

For the binary distribution, edit

atlassian-jira/WEB-INF/classes/professionalupgrades.xml, line 59, and change:

<upgrade build="48">

to:

<upgrade build="48" setup="true">

In the source distribution, the same file can be found in
src/etc/upgrade/professionalupgrades.xml

Then restart JIRA, and the problem should be resolved.

--Jeff