samtools view: writing to standard output failed: Broken pipe
[W::sam_read1] Parse error at line 1
samtools sort: truncated file. Aborting


SAMtools sort has been unable to parse its input, which it thought was SAM (mostly because it couldn't be recognised as another format e.g. BAM).

This is because sed 's/^/LP1-/' is putting LP1- at the front of every line. If the output of samtools fixmate is SAM, then this LP1 is garbling the SAM header lines. If the output of samtools fixmate is BAM (as it probably is), this LP1 is completely garbling the data.

What were you trying to achieve with this sed command?