# Error when using --bypass-trim **URL:** \ **Category:** KneadData\ **Created:** [August 11, 2023, 7:12pm UTC](https://forum.biobakery.org/t/error-when-using-bypass-trim/5761 "2023-08-11T19:12:45Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![danpal](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.biobakery.org/danpal/32/2343_2.png) [@danpal](https://forum.biobakery.org/u/danpal)\ **Post date:** [August 11, 2023, 7:12pm UTC](https://forum.biobakery.org/t/error-when-using-bypass-trim/5761/1 "2023-08-11T19:12:45Z")
kneaddata v0.12.0 I have some files with names sample1\_R1.fastq.gz and sample1\_R2.fastq.gz. When running `kneaddata` with the option `--bypass-trim` the next error occurs: ```auto Decompressing gzipped file ... Decompressing gzipped file ... Reformatting file sequence identifiers ... Reformatting file sequence identifiers ... Initial number of reads ( /A2/danielpalma/projects/smk-metagenome/resources/test/fastq/knead/kneaddata_output/reformatted_identifiers4vawf0jt_decompressed_9r8knfr8_sample1_R1 ): 191296.0 Initial number of reads ( /A2/danielpalma/projects/smk-metagenome/resources/test/fastq/knead/kneaddata_output/reformatted_identifiersef0c7wrw_decompressed_hel63yku_sample1_R2 ): 191296.0 Running fastqc ... Bypass trimming Total reads after trimming ( /A2/danielpalma/projects/smk-metagenome/resources/test/fastq/knead/kneaddata_output/reformatted_identifiers4vawf0jt_decompressed_9r8knfr8_sample1_R1 ): 191296.0 Total reads after trimming ( /A2/danielpalma/projects/smk-metagenome/resources/test/fastq/knead/kneaddata_output/reformatted_identifiersef0c7wrw_decompressed_hel63yku_sample1_R2 ): 191296.0 ERROR: Unable to write file: /A2/danielpalma/projects/smk-metagenome/resources/test/fastq/knead/kneaddata_output/reformatted_identifiers4vawf0jt_decompressed_9r8knfr8_sample1_R1 ``` But if I rename the files to sample1.1.fastq.gz and sample1.2.fastq.gz all its ok. I can work with that but it is a little inconvenient