The popularity of the city’s free classes through the Department of Parks and Recreation is believed to have crashed the registration website yet again, a department spokesman said.

Online registration for the Parks Department’s spring classes — from archery to Zumba — officially began at 9 a.m. today.

Many who hopped online and tried to register initially got a “service unavailable message,” said DPR spokesman Nathan Serota, but anyone who is interested should continue trying.

“It was kind of a rough start,” said Serota. “Little by little, it came back online. It was one of those things, if you kept trying, it worked out. Most everyone ended up getting through.”

The glitch was likely due to the high volume when registration first opened up, he said.

In August, the website crashed for two days in a row when fall class registration opened, possibly because of high traffic, the Parks Department said.

Honolulu residents have until 11:59 p.m. on Jan. 10 to register for classes online.

Anyone who misses the online registration window for free classes may still register during walk-in registration periods — if space is still available.

Walk-in registration will be held at individual park sites according to the following schedule:

>> District I (Hawaii Kai to McCully) and District II (Makiki to Aiea), 6 to 8 p.m., Jan. 14 and 2 to 5 p.m., Jan. 15 and 16.

>> District III (Pearlridge to Waianae to Wahiawa), District IV (Waialua to Waimanalo), and District V (Patsy T. Mink Central Oahu Regional Park), 6 to 8 p.m., Jan. 15 and 2 to 5 p.m., Jan. 16 and 17.

More information is available at this link.