make.contigs error on mothurGUI using Illumina SOP

I am using the illumina SOP on mothurGUI and I just run the make.contigs and at the end of the process I got the following error and I cannot figure out what I did wrong

processes reported processing 4932422 sequences, but group file indicates you have 4932423 sequences. Either you have a file mismatch or a process failed to complete the task assigned to it.

Is that error message from the make.table command? The numbers are very close. Have you tried rerunning make.contigs with processors=1?