Forum Discussion
I too had this issue. Known bug and it is with dev to fix. Support gave me this workaround.
The issue has been identified when there are no Custom fields enabled for the Project, the bulk assign does not work. So as a workaround, we suggest creating a Custom field and enabling it, post which it will work.
We are able to reproduce the issue, and the internal defect has been raised to our development team. They're working on a priority to resolve the issue.
As a workaround, please navigate to settings - apps - Custom fields under Zephyr Squad - add any execution Custom field.
Now navigate to the affected project - click on Zephyr Squad menu - Custom fields - select execution tab - enable the created custom field.
Now, try to assign the execution to users, and you should be able to do the same.