Nightly Network Inventory job error

Hi Team,

i can see below error under log for my scheduled "Nightly Network Inventory" job.

"ERROR: Job execution error : 91 - Object variable or With block variable not set"

we are using below platform.

orion platform 2017.3.2.sp2

NCM 7.7

NPM 12.2

can some one help me to resolve this?