If a user is unable to access Batch Gift Entry (BGE) in either sandbox or production, the first and most critical troubleshooting step is to verify that the BGE add-on license has been manually applied to their org.
Even if the package is installed and the user has the correct permissions, BGE will not function until the add-on license is applied.
The same applies to Scheduler: even if the customer installs the Scheduler package, the add-on license must be manually applied for features such as Scheduled Document Generation and Scheduled Reports to work.
This license check should always be Step 1 in troubleshooting BGE or Scheduler access issues in both sandbox and production environments.