rsem-run-em failed with no reasons

[Kartika]

rssem runs and build index and run-em also shows logs (n reads processed...). But after that it shows like - 

rsem-run-em    

cDNA_hap12 1 

path/AP7290021 

path/AP7290021.temp/AP7290021 

path/AP7290021.stat/AP7290021 -p 20 -b 

path/AP7290021.temp/AP7290021.bam 0 " failed! Plase check if you provide correct parameters/options for the pipeline!

"Exited with exit code 255."

Command I gave - 

rsem-calculate-expression -p 20 --bowtie2  <read_path>/AP7290021-singles-trim.fq ./cDNA_hap12/cDNA_hap12  <output_path>/AP7290021

Please suggest a solution soon.