This is bizarre… Take a look at the following HTML and CSS. Once the fieldset is processed and turned into a series of div elements (in the character sheet sandbox), the action button will be inside of a div with its CSS position property explicitly set to static (but setting it to anything(?)—definitely relative or static—has the same effect). When an action button is a child of such a div, the on("clicked:repeating_skills:activate", ...) handler registration has no effect. If you comment out the “position: static” CSS, event handler registration works as expected. This is the simplest version of an issue that’s affecting my sheet development. Has anyone else encountered this? Setting position on containers seems like one of the most common CSS patterns so this must be a bug, right? <fieldset class="repeating_skills"> <button type="action" name="act_activate">Activate!</button> </fieldset> <script type="text/worker"> on("clicked:repeating_skills:activate", function() { console.log("Activate button clicked"); }); </script> .ui-dialog > .dialog > .tab-content > .sheetform > .charsheet div { position: static; /* Breaks repeating section action button event handlers. */ }