Computer problems thwarted the distribution Monday of free timed passes for early next year to the National Museum of African American History and Culture.

Timed passes for January through March were supposed to be distributed Monday morning starting at 9 a.m. on the museum’s website, nmaahc.si.edu. But minutes after 9 a.m., the website showed no tickets left for any day in 2017.

A Smithsonian spokeswoman said that the problem was with the vendor, E-Tix, and that the passes were not sold out.

Passes also can be obtained by calling at 866-297-4020 from 9 a.m. to 8 p.m. Monday through Saturday and from noon to 8 p.m. Sunday. But that service was not working Monday either.

The museum, which is open from 10 a.m. to 5:30 p.m. daily, is requiring visitors to obtain free passes with a designated time slot in order to control crowds and reduce wait times at the entrances. Even with the passes, however, visitors have reported long lines at the exhibitions, cafe and gift shop.

Museum officials said they had distributed 705, 809 passes for the first three months after the Sept. 24 opening, for an average of 7,200 daily. The passes will be required indefinitely, and visitors are not admitted earlier than their designated time.

In addition, the museum stopped offering in-person passes Sunday, just six days after opening, to reduce crowds. The number of same-day passes (distributed starting at 9:15 a.m. for that day’s use) varied daily but topped out “in the hundreds,” the spokeswoman said.