Trouble with plot.estimateEffect

[nms001]

I keep running into an issue when trying to use stm's plot.estimateEffect function, similar to #16. The plot I am trying to create is the expected topic proportion over time. Here is the code I use:

russia_stm_10 <- stm(documents = russia_out$documents, vocab = russia_out$vocab,
                    K = 10, prevalence = ~party_id + splines::bs(date) + region + speak_type
                    + speech_type, data = russia_out$meta, init.type = 'Spectral', 
                    seed = 710)
                    
russia_prep_10 <- estimateEffect(1:10 ~party_id + splines::bs(date) + region + speak_type + speech_type,
                                russia_stm_10, metadata = russia_out$meta,
                                uncertainty = 'Global')

plot.estimateEffect(russia_prep_10, covariate = 'date', topics = 4,
                    method = 'continuous')

The error I get is Error: object 'cdata' not found. I have also tried running plot.estimateEffect(russia_prep_10, covariate = 'party_id', topics = 4, method = 'pointestimate'), but the error I get instead is Error in `[.data.frame`(cdata, , names(prep$data)) : undefined columns selected

Here is a description of the variables I'm using:

• party_id indicates the party of an American presidential administration
• date indicates the day/month/year a president gave a speech
• region indicates the geographical location where a president gave a speech (e.g., Europe, North America, East Asia, etc.)
• speak_type indicates whether the speech was given by the president or one of their staff
• speech_type indicates whether spoken remarks were given in a speech or an interview

Thanks!