Hi

I have used scythe to trim adapters and am now using sickle to quality trim. 1 out if 20 files has come with the error below (19/20 seem to be fine). Can anyone suggest why this is happening and how I can solve this issue?

Thanks
Sangita

msxsb3@msngs:~/projects/uPAR_overexp/2a_D1_E4_EV_24$ /home/msxsb3/projects/uPAR_overexp/scythe_sickle/sickle-master/sickle pe -f 2aR1trimmed_sequences.fastq -r 2aR2trimmed_sequences.fastq -t sanger -o qtrim.1.fastq -p qtrim.2.fastq -s qtrim.unpaired.fastq -q 20 -l 20

ERROR: Quality value (0) does not fall within correct range for Sanger encoding.
Range for Sanger encoding: 33-126
FastQ record: NS500557:5:H3F3HBGXX:3:21509:25794:14643
Quality string: .A)AAFFFAF.FFFAFAFF<FFF.FFFFFFFFFF<FFFFFFFFFFFFFFFF<FF<FF<F.FFFAFFF7FFFFFFF
Quality char: ''
Quality position: 76