A group have Create, Modify and Read access to a folder. When a user of that group login & try to trigger a workflow on any of assets which are under that particular folder observes that Start Workflow button in timeline is disabled. What permissions as to be assigned to a user so that he can select the workflow from Start workflow button with out violating above three permissions on that folder.
@rsl_lucky In order for a user to trigger the start workflow on any of the assets the user should have permissions on the /var/workflow/models and /var/workflow/instances folder in addition to the other permissions that you have already provided.
For more details please also check the below document: