VMware Converter is a great tool but it has some (documented) limitations.
For example, the number of supported Symantec BESR versions is limited.
Is there any alternate, maybe third party Solution we can try to P2V PCs and servers?
PlateSpin & Double Take tool available but you have to pay for it.
Have a look at this , might help
PlateSpin is good stuff, Quest (Probably Dell now) has a tool that's pretty good, Acronis has a SMB tool.
Just a suggestion, if you can rebuild the system, I would go for that first. I feel like every time I P2V a system, it's not near as clean as building it fresh on a server template optimized for virtual environments.