Comment 4 for bug 1509270

Maybe the problem is in /usr/share/ubuntu-release-upgrader/gtkbuilder/DistUpgrade.ui, line 1158:

<property name="label" translatable="yes">&lt;b&gt;&lt;big&gt;Upgrading Ubuntu to version 15.04&lt;/big&gt;&lt;/b&gt;</property>

But changing the line to 15.10 does not help.