It's a catch all error. Basically I tried to keep all error messages the same as the previous API where possible, but some didn't have an equivalent. If you email the diagnostic log to
admin@gruss-software.co.uk I can have a look and see what the exact error was. It might be there is a more appropriate code I could have used.
Select open settings folder from the options menu to find the diagnostic logs folder. Please email the file from the date this error occurred.