Hello, I am trying to map Illumina paired-ends reads from the nematode Caenorhabditis briggsae. Here are the steps of my history: 1)I uploaded and groomed two .fq files corresponding to paired-end reads. In the attributes, I choose the cb4 database. 2)I mapped them using BWA (BWA Version: 0.5.9-r16 BWA run on paired-end data). However, I used the cb3 database here, since the cb4 was not available. 3)I filtered the output SAM file for mapped reads (galaxy tool version 1.0.0). cb3 is still said to be the reference database in the filtered SAM I got as output. 4) Then I tried to convert the SAM into BAM. Here it failed. When I chose the parameters of this tool, what I had for the 1st option "Choose the source for the reference list" is either: -from the history -locally cached I chose locally cached. Then, when running the tool, and I had this message error: "20: SAM-to-BAM on data 16: converted BAM error An error occurred with this dataset: Samtools Version: 0.1.18 (r982:295) No sequences are available for build (cb3), request them by reporting this error." As recommended, I report you now this error ! I found a similar problem in the Galaxy_user mailing list... But I did not get how the problem was solved ! http://user.list.galaxyproject.org/SAM-to-BAM-conversion-problem-td4135498.h... I tried to change the attributes of the SAM and filtered-SAM files to cb4, but it did not work. Note also that in the error report, the version is said to be 0.1.18. But when I click on the SAM-to-BAM tool, the header of the page says: SAM-to-BAM (version 1.1.2). I don't know if this matters or not. Could you please help me fixing this issue ? Many thanks ! -- Fabrice Besnard Institute of Biology of the Ecole Normale Supérieure (IBENS) 46 rue d'Ulm, 75230 Paris cedex 05, France 8th floor. Office: Room 802. Lab: Room 817. mail: fbesnard@biologie.ens.fr Tel: +33-1-44-32-39-44