Just a couple of tips if you weren't already aware about tidying your SABRE Workspaces.

Banner messages which appear at the top of your Workspace list can be deleted once read or once the warning is over. At the bottom of the message click where it states "Remove message".

Also, if you have a lot of unwanted "To be assigned" reports then there are two ways of dealing with these. Since they are still in draft format, you can use those as templates for new reports. Just simply open the report and change any of the detail already entered or blank. You can even toggle between event and reaction forms.

Otherwise, you can try and just delete them. Very old reports can't be deleted, so will have to be dealt with as above. But newer report can simply be deleted by opening the report and clicking the delete button.