Hi,
[Thr 6968] JHVM_LoadJavaVM: Java VM created OK.
[Thr 6968] *** ERROR => Can't load main class [com.sap.engine.boot.Start] [jhvmxx
Kindly check the permission of directory and files in /usr/sap/<SID>/<instance>/j2ee/cluster/bootstrap.
Could you check and paste the files dev_bootstrap & std_bootstrap.out from work directory.
Please go through the link for further information http://myhelp.uky.edu/bw/en/c2/2f2c4142aef623e10000000a155106/frameset.htm
Regards,
Nikhil