xml - Unix fails to load external entity when New line in text file -

i using unix c shell.

my requirement: read multiple xml files r drive (different working directory) , put them in output file. filepaths of above xml files written in notepad txt file (exp.txt) placed in working directory.

current exp.txt content (single xml file path):

/mnt/fusionoatsresults/reeresults/19jul2016/dtegroup/7899464/152877508_1/session1/basicreport.htm_source.xml 

current working command:

foreach xmlfile ( "`cat exp.txt`" ) xmlstarlet sel -t -m '//result_step' -v '@time_stamp' -o '|' -v '@step_name' --nl "$xmlfile" >> /scratch/ryerrams/view_storage/outputfile.txt end 

the above command works perfectly.

but, when add newline in exp.txt file read second xml file also, fails.

new 'exp.txt' content:

/mnt/fusionoatsresults/reeresults/19jul2016/dtegroup/7899464/152877508_1/session1/basicreport.htm_source.xml /mnt/fusionoatsresults/reeresults/19jul2016/dtegroup/7899464/152877536_1/session1/basicreport.htm_source.xml 

current command:

foreach xmlfile ( "`cat exp.txt`" ) xmlstarlet sel -t -m '//result_step' -v '@time_stamp' -o '|' -v '@step_name' --nl "$xmlfile" >> /scratch/ryerrams/view_storage/outputfile.txt end 

i below error message:

failed load external entity `"/mnt/fusionoatsresults/reeresults/19jul2016/dtegroup/7899464/152877508_1/session1/basicreport.htm_so"rce.xml` 

what missing? please suggest. thanks.