currency swap question

Hi Tutor, hope you are well! I have a question regarding 2017JuneQ3a, I understand the meaning of the following sentence and the meaning of exchange control to the company, but I don’t understand how it is a disadvantage of currency swap and how the control is associated with currency swap? It suggests the drawback is that “If the government decides to impose exchange controls in Wirtonia, Buryecs Co may not be able to realise the receipt at the end of Year 3, but will still have to fulfil the swap contract.” Thanks in advance!