Which of the following is not a valid reason for an NDEA to enter a voucher for a traveler?

A traveler not being properly trained in DTS (Defense Travel System) use is not a valid reason for a Non-DTS Entry Agent (NDEA) to enter a voucher. Training in the system is essential for effective travel processing; however, it is the responsibility of the traveler to ensure they understand how to use DTS for their travel arrangements, and this does not impact the legitimacy of their travel.

On the other hand, valid reasons for not processing a voucher include situations where the traveler is traveling for personal reasons, which falls outside official travel parameters and would not warrant reimbursement. Additionally, a missing travel authorization indicates that the proper approvals were not secured, which is critical for processing. Lastly, lacking necessary documentation directly impacts the validation of expenses incurred during travel and is essential for processing any claims. Thus, A stands out as not a legitimate reason in the context of the other options.