对服务中的NullReference异常进行故障排除

I have a windows service that runs various system monitoring operations. However, when running SNMP related checks, I always get a NullReference exception. The code runs fine when run through the user interface (under my username and password), but always errors running as the service. I've tried running the service as different user accounts (including mine), with no luck. I've tried replacing the SNMP monitoring code with calling the PowerShell cmdlet get-snmp (from the /n NetCmdlets), but that yields the same error.I have a windows service that runs various syst