Problem
Users cannot see the issues after migrating a project from the Server/DC to the Cloud.
Solution
In Jira Cloud, one condition is necessary and sufficient for a user to view a project's issues. The user must have the “Browse Project” permission in the Permission Scheme assigned to the respective project. Even if a user is an administrator, he cannot see the project issues if he doesn’t does not have the “Browse Project” permission in the respective permission scheme.
Using the account used for the migration also doesn’t does not guarantee that the user will have the necessary permissions.
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Log in with a user that has permission to edit permission schemes. An administrator user should work.
Identify and edit the permission scheme assigned to the migrated project.
Give “Browse Project” permission to the users/groups/roles that should be able to see the project issues.
Note: If a user with a given mail on the server has permission to view the project , and on the server with a specific email address but cannot view the issue on the cloud the user with the same mail does not, a possible reason may be that the “Browse Project” permission on the server is given to a Group that the user is a member of. On the cloud, we create groups but do not populate them with users because of the way Jira manages groupsemail address, it could be that on the server, the "Browse Project" permission granted to a group the user belongs to. On the other hand, on the cloud, CMJ will only create empty groups without users.