SQLWATCH contains many components that are invoked by the SQL Agent Jobs or Windows Task Scheduler. Any failures should manifest in these tasks failing.
SQLWATCH also contains a number of default self-checks (checks with the negative IDs) that ensure correct the execution. You can list any problematic checks with the below query. Running this on the central repository will also evalaute all remote instances, including any import errors:
select *from [dbo].[vw_sqlwatch_report_dim_check]where(-- get all critical and warning checks:(last_check_status in ('CRITICAL','WARNING') or last_check_status is null)-- but exclude performance and backup checks:and check_id not in (-43,-37,-36,-34,-33,-32,-30,-29,-28,-25,-24,-23,-22,-20,-19,-18,-17)-- and list any checks that are failing or never run:or (last_check_status = 'CHECK ERROR' or last_check_status is null))