Multivariate: Error with test samples


I'm currently trying to do an OPLS-DA analysis using test samples. I have added to the SmpleMetada a column "test." where I have filled with "yes" or "no" depending on the samples. But I have got this error:

Error in .local(x, y, ...) :
'parAsColFcVn' vector length must be equal to the number of 'x' rows
Calls: plot -> plot -> .local
Execution halted

Can someone help me with this error?
Thanks in advance,