Beatles

I have a similar scenario;losses over 3 previous years and a profit in the last, amounting to less than the losses brought forward. As instructed by the ‘Help’, I have entered only the profit amount in ‘losses brought forward to be offset against this year’s profit’ and carried the remainder forward to be used against future profits. The problem I have is that when the calculation is ‘checked’, a red warning is displayed for that section asking me to recheck my figures which I’ve done many times but still the red warning. I’ve tried calling HMRC to discuss but no answer after an hour of waiting. What do I do please?,time is running out!