ARTEMIS processAlignments() returns "missing values are not allowed in subscripted assignments of data frames"

Hi all,
I am executing the ARTEMIS user script against a breast cancer cohort. Everything looks fine until I get to the first post-processing step.
When I run this

processedAll <- output_all %>% processAlignments(regimenCombine = 28, regimens = regimens)

I get this error:

Performing post-processing of 1559 patients. Total alignments: 6888 
Error in [<-.data.frame(*tmp*, drugDF$V2 == i, , value = list(V1 = NA_character_, : missing values are not allowed in subscripted assignments of data frames 
7. stop("missing values are not allowed in subscripted assignments of data frames") 
6. [<-.data.frame(*tmp*, drugDF$V2 == i, , value = structure(list( V1 = NA_character_, V2 = NA_character_, t_start = NA_real_, regimen = NA_character_, index = NA_integer_, ymin = NA_real_, ymax = NA_real_), row.names = "NA", class = "data.frame")) 
5. [<-(*tmp*, drugDF$V2 == i, , value = structure(list(V1 = NA_character_, V2 = NA_character_, t_start = NA_real_, regimen = NA_character_, index = NA_integer_, ymin = NA_real_, ymax = NA_real_), row.names = "NA", class = "data.frame")) 
4. createDrugDF(drugRec) 
3. processed <- plotOutput(newOutput, regimenCombine = regimenCombine, returnDat = T, returnDrugs = FALSE) at generateRawAlignments_local.R#151 
2. processAlignments(., regimenCombine = 28, regimens = regimens) 
1. output_all %>% processAlignments(regimenCombine = 28, regimens = regimens)

What could be the reason?