Asignee not able to sign

[olajohn]

I have two issues with countersign signature. I've spent about 3 weeks without success.

1. When Admin sent a document for signature, through the workflow, the assignee is not able to sign. Coutersign throws a permission error: org.alfresco.repo.security.permissions.AccessDeniedException: 04020023 Access Denied. You do not have the appropriate permissions to perform this operation.
2. I need a kind of step by step instruction to setup a trusted store and generate trusted certificates.

Alfresco 4.2.f on windows 8.1

I will really appreciate if my challenges can end with you. Thank in anticipation.

Olajohn Abolade