Did you ever get this figured out? We have the same issues, but it's random, not very consistent.
We are getting this error pretty regularly. Any update on this issue?
We are running into a similar issue while deploying patches on servers with 7.4.3 agents using 8.0 BL Application servers. After the deploy job failure, we upgraded one agent to 8.0+ version and the deploy job went through. It is possible this is happening becaues of the agent version mismatch. But it is not conclusive yet. Has anyone tried to upgrade the agents and check if the same error occurs again?
Here are my observations and hopefully you have the same issue and can be resolved:
I was trying to run patch analysis and deploy jobs with 8.0.0 sp4 application servers and 18.104.22.1681 agents. The analysis works but patch deploy jobs fail to commit after running through simulate and stage phases. I see the same error message as you posted.
From my research, path to cab files is hardcoded in pre 7.4.5 agents. With 8.0 version of the agent, BL strictly moved to using xml version of shavlik files. When these xml files are passed to the agents during the deploy jobs, the agent which is at 7.4.3 fails to understand the xml version while it is expecting to read a cab version of the bldeploy file. Hence the error message "Could not load patch details file".
Upgrading the agent to atleast 7.5.0 and above should resolve this issue. It's always recommended to use the same agent version as that of the application server.