I sent an invitation through Signavio to a new user and when they clicked on the link, they are seeing a 30-day trial notice, even though I registered them.
Please check if the user already has a Process Manager license.
This issue can occur if a user who has already accepted their invitation, uses the Register URL i.e. https://editor.signavio.com/p/register
Given they have already accepted the invitation, they would need to use the normal URL i.e. https://editor.signavio.com
From there, they will be able to see the Workspaces they are a member of.
KBA , BPI-SIG-CA-SEC-UM-IN , Invitations / License Management for SAP Signavio , How To