Error in rarefaction.single mothur 1.24.1 linux 64bit

while running
rarefaction.single(freq=100, iters=10000, processors=4)
I get all the .rarefaction files but then:

[ERROR]: Could not open .../
[ERROR]:  has occurred in the RareFactCommand class function createGroupFile. Please contact Pat Schloss at, and be sure to include the mothur.logFile with your inquiry.

AD1d_H_bac is my sample name and there’s a file called which seems fine
but there isn’t any file


Thanks for reporting this issue. Group names that include “_” are causing a parsing error in the creation of the groups.rarefaction file. This will be fixed in the next release, but in the meantime you can run the command with groupmode=false.