Online Foreign Tax Credit Relief

I want to claim Foreign Tax Credit Relief on the Capital Gain from the sale of a residential property in Switzerland on which I paid Swiss capital gain tax of £1661. The amount of UK CGT is in excess of the Swiss tax paid. I put the figure in the HMRC online tax return thus: In “Fill in your return” Capital gains- foreign tax credit relief and Special Withholding Tax section, I entered the amount of £1661 in Foreign Tax Paid. When I finish the return and go to “View your calculation” it states “We have calculated your Total foreign tax credit relief on gains: £0.00 This doesn't seem right. How can I correct this?

Hi
The foreign tax credit can be up to 100% of the overseas tax paid.  
If the UK capital gains tax is greater than the Swiss equivalent, then you can claim 100% against the UK CGT liability.  
You will be asked if you agree with the self assessment calculated figure, please select no and you will be prompted to enter your own figure and explanation.  
The explanation is as you mentioned, the UK CGT is greater than the Swiss tax paid.