The button "New" is greyed out in the Explorer.
Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental.
This issue is related to the access rights. You have to contact an administrator of the workspace to check the access rights for your profile.
If you are an administrator, you can check this article explaining how to define the access rights under this link: https://docs.signavio.com/userguide/editor/en/workspace_admin/manage_users_access/managing_access_rights_diagrams_dictionary.html
KBA , BPI-SIG-PM-EXP , Explorer for SAP Signavio Process Manager , How To