Description of the problem
Your Active Directory has more than 1,000 users. When importing users into Open Bee™ Portal only the first 1,000 are offered to you to be imported.
Cause
Default one Active Directory applies a pagination of 1,000 items per page in the functions used by Open Bee™ Portal to import users. In versions < 6.4 , Open Bee™ Portal only processes the first page.
Solution
Solution 1: Change the setting MaxPageSize in your AD configuration: https://support.microsoft.com/en-us/kb/315071
Solution 2: Update to Open Bee™ Portal version 6.4 or higher.