Add button is not visible to ITIL to add multiple incident in Problem related list

[prit123]

Add button is not visible for ITIL user to add multiple incident in Problem related list. It is visible only to admin users. Below is the screenshot of admin user-

[prit123]

@Kieran Anson - I have checked below things you mentioned-

1 .User can edit problem ticket. Though new GlideRecord(current.getTableName())).canWrite() gives false. What can be the reason. 

2. Yes there is a system property of 'com.snc.incident.link_to_task.problem' with a value of 'problem_id'

3. Yes the problem is active.

4. The user has ITIL role.

[Kieran Anson]

If 1 is returning false, then they're not passing an ACL to allow write to the record, you'll need to debug the ACLs for the user and see whether they're missing the relevant permssions, and/or the ACLs are condition based on something like the state of the problem