Affects Version/s: 7.0.X, 7.1.X, Master
Steps to reproduce:
1. Set up a vanilla Liferay.
2. Create a web content folder and assign the Single Approver workflow to it.
3. Create a new user and add him to the site, then assign him the Site Content Reviewer role for that site.
4. Create a web content in that folder and submit for publication.
Checkpoint: no error in Tomcat console, and the site content reviwer user gets a workflow task and notification about it
5. Delete the Site Content Reviewer role
6. Do step 4 again
Result: "com.liferay.portal.kernel.exception.NoSuchRoleException: No Role exists with the primary key 30230" in console, and the user created at step 3 does not get a workflow task and notification
Recreating manually a site role called Site Content Reviewer and assigning it to the user from step 3 does not help. The same happens when you try to submit a content for publication.