Steps to reproduce:

1. Create CT (ie. a Form name 'testform')
2. Publish created CT
3. Go to Forms
4. Click on edit button for 'testform'
5. Make changes to 'testform'
6. Click on 'send to review' button and send 'testform' to Administrator for a review
7. Go to Forms 
8. Delete 'testform'
9. Go to 'View notifications' 
10. Click on 'Sent to trash' link for 'testform'

Actual result:

Error 500 occurs:

Return value of EzSystems\EzPlatformAdminUi\EventListener\SetViewParametersListener::resolveParentLocation() must be an instance of eZ\Publish\API\Repository\Values\Content\Location, bool returned

Expected result: 

Error message is shown / User is redirected to trash?