Ascend runDESeq() not finding factors

Question

[cf556]

Hello, I am not sure if this is the best place to post this, but I figured here I have the best chance of getting an answer, currently I am trying to run ascend's runDESeq() function and am getting the following error.

runDESeq(em.set, group = "cluster", parallel = FALSE, method = "pooled-CR")

Error in `contrasts<-`(`*tmp*`, value = contr.funs[1 + isOF[nn]]) : contrasts can be applied only to factors with 2 or more levels

Now as far as I can tell I should have at least two levels as there are three clusters, I am not sure what I am doing wrong. Any advice is appreciated.

[Ram]

Is cluster a factor or just a character class vector?