After an upgrade to the Bamboo 5, various pages have bad placement of labels and texts:

Cause

The problem is caused by the "Bamboo Sonar Tasks" plugin not being compatible with Bamboo 5.0: Bamboo Sonar Tasks incompatible with Bamboo 5.0.

Workaround

Navigate to Bamboo Administration - > Plugins - > Manage Add-ons, disable Bamboo Sonar Tasks, Bamboo Sonar Web plugins and restart Bamboo. Check for any other third party plugins  that are enabled and were compatible with the previous version of Bamboo installed on the server, but are not compatible with Bamboo 5.0 yet and disable them as well to avoid other issues with the new installation.