Hello, @alnrob. Getting an error when trying to complete an action like managing currencies in your PayPal account is certainly no good!
Please take a look at https://www.paypal.com/au/smarthelp/article/faq532 for more information, and please try logging off from everything on your computer, deleting the cookies and temporary internet files (via Windows Control Panels including Java, Internet Options and Flash Player, if that applies) and then re-starting your system. That often helps clear up problems such as the one you described.
I hope this is helpful. Thanks for being a part of the PayPal Community!
Sincerely,
Michael
PayPal_Michael
