UK Pensioners payroll generates blank warning messages

Summary:

UK Pensioners payroll calculation generates two warning messages with no description in the UI

Content (please ensure you mask any confidential information):

UK Pensioners payroll when calculated generates these warning messages in the UI:

There is no message description and no details in the UI. When we run the payroll messages report however, we do get some detail:

Pensioners are on NI category X, so that explains the first message.

I'm guessing that as the pension payment is not NIable, the second message might be saying there is no NIable earnings, but it's a strange message code if it is that.