Some RodeoHouston fans ran into a frustrating roadblock when tickets went on sale Thursday morning. 

Their pages were expiring in the process of buying tickets for their favorite entertainers. Hundreds of people complained on  RodeoHouston's Facebook and Twitter pages.

"Nobody got anything, so I wasted my whole morning not working, not doing the things that I'm supposed to be doing because I was in line trying to get tickets and I didn't get anything," Didi Rodriguez told us. She was trying to get George Strait tickets. 

RELATED: Complete 2019 RodeoHouston lineup

RodeoHouston President Joel Cowley apologized to the fans. 

 "We feel their frustration. There was a particularly malicious bot that affected one of the servers," Cowley explained. "He said they have 50 servers deployed and the only way to shut down that bot was to close that server. So any customers who were on that server, they received this error message."

Cowley said 30,000 people were in the George Strait waiting room alone when ticket sales began.

George Strait tickets quickly sold out so fans will probably have to pay big bucks to see him.

"You go to Vividseats, you go to StubHub and you go to AXS and everything is like a $1,000," Rodriguez said. "It's cheaper to get on a Spirit airline flight and go to Vegas and watch George Strait there."

Cardi B. and Chris Stapleton were also sold out at last check. Tickets are still available for 18 other shows, including Luke Bryan, Brooks & Dunn and Kings of Leon.

Tap here for buy tickets.