This error suggests that SolrMarc is trying to load a custom BeanShell indexing routine but is having trouble. The callnumber.bsh script is not turned on by default, so you probably customized one of these lines in import/marc_local.properties:
#callnumber = script(callnumber.bsh), getFullCallNumber(099ab:090ab:050ab)
#callnumber-subject = script(callnumber.bsh), getCallNumberSubject(090a:050a), callnumber_subject_map.properties
#callnumber-subject-code = script(callnumber.bsh), getCallNumberSubject(090a:050a)
#callnumber-label = script(callnumber.bsh), getCallNumberLabel(090a:050a)
Assuming that this was intentional, you should check import/index_scripts/callnumber.bsh to see if there are any obvious errors (it might be useful to compare it against the standard trunk version to see what, if anything, has been customized).
Hopefully you can either correct problems with the script (if you have a reason to use the script) or simply comment out the relevant line(s) in your configuration (if they were enabled by accident).