Project Timeline - Cannot create issues when required fields are configured in workflow validator rather than field configuration

Problem
In case there are certain fields required for specific issue types and this requirement condition is modelled with a workflow validator, JSW Project Timeline won't bring up the Create issue dialog when trying to commit an issue of this type to JIRA and hence the issue creation will fail.

Steps to Reproduce

Navigate to the workflow configuration page and select one to edit. 

View the workflow digram and select the Create Issue transition. 

Select the validators link and add a Field Required Validator

**Publish the changes to the workflow

Returning to the the timeline, and try to create an issue.

Result

The creation fails and an error flag is displayed.

Workaround
Configure the required field via field configurations and screens and specify the field behaviour this way.

Notes
The workaround doesn't apply to system fields that are locked by default (ie. Parent Link, Team)