Ticket sales for Two Castles 10k will reopen on Wednesday with 4,000 places still available for runners, promise organisers.
The ticket site to register for the popular road race crashed less than half an hour after opening for registrations at midday on March 1 in what organisers blamed on a “malicious distributed denial of service attack” on the page.
So far, only 53 people are signed up to the event which expects to see thousands of runners head from Warwick Castle to Kenilworth Castle on June 12.
Race entries will reopen at 8.30am on March 2 after the problems saw the website closed off on Tuesday afternoon.
A statement from the organisers read: “On behalf of the Two Castles Run and our registration partner, Full On sport, we would like to apologise to everyone who was unable to register earlier today due to technical problems.
“We apologise and understand the frustrations this has caused to many of you trying to register today.
“As a result we took the difficult decisions to suspend registrations until these problems had been resolved.
“There are still over 4,000 places available.”
The race is organised by the Rotary Club of Kenilworth and Leamington Cycling and Athletics Club and the error was put down to the server being “overloaded with a denial of service (DOS) attacks maliciously trying to sabotage the event or the entry system”.
Hundreds of angry runners vented their frustrations at being unable to enter the race on Tuesday.
Others slammed the new registration time as being “unacceptable” for working people or parents on a school run, with tickets expected to sell out within hours once the new site launches.
Runner, Steve Malin, said after spending hours trying and sign up on Tuesday afternoon, he now has “no chance” of getting a place with a new rush expected in the morning.
He said: “I have done this race every year for the past eight years and sat for three hours trying to register toady with no luck.
“There is just no way I will get a place now, I cannot get to a computer at 8.30am and am sure many others will have the same problem if they are heading to work or on the school run.
“Tickets will be sold out within hours and we have wasted all this time today, it is a shambles. I am so disappointed.”
The tickets will be available here from 8.30am.