LUMPY problem bam

Hello, can anyone help me?
Im having some issues with LUMPY preprocessing:

I have a WGS sample. i aligned it with BWA-MEM and my outputs seems to be ok.
But when i use “LUMPY_preprocessing” to extracts discordant read pairs and split-read its no working due to: file does not contain alignment data

Does anybody has already used this LUMPY tool?
Is there any BWA-MEM parameter to set before lumpy_preprocessing??

Thanks in advance