Hello, we encountered this same issue when we also tried to upgrade and I actually saw your post when we were looking for a solution. Ultimately, we were able to find out that there was a conflict with something else we had installed on the host. Can you try to look in /var/log/messages after trying to start splunk? In our case, we observed the following message: Aug 7 00:22:54 <splunk_host> kernel: splunkd[53109] trap invalid opcode ip:XXXXXXX sp:XXXXXXXXXX error:0 in <non_splunk_agent>.so[XXXXXX+XXXXX] After we saw that, we were able to uninstall the agent and splunk was able to start normally on the search head. ... View more