Your SENCO will need to have a specific qualification recorded on their profile, unless they began their role a year or more prior to 1st September 2009. This can be done by clicking on the Qualification cog on their profile:
The Qualification subject is Z201 SEN-SENCO. A Qualification Code will also need selecting from the top dropdown. Normally the SENCO qualification is taken as part of a Masters degree. If that is not appropriate, e.g. it was taken as a free standing qualification, it is advised to record it as NQF4. Once saved, recalculate the workforce census and this query will leave.