Error Post Upgradation

[infofedsec]

Hi- I have upgraded my Nagios XI from 5.8 to 5.11. post upgrade I am not able to add any host as it is giving error on template. I checked everythiing but I am not able to find the out the issue. the Error looks like this

Error: Template '' specified in host definition could not be not found (config file '/usr/local/nagios/etc/hosttemplates.cfg', starting on line 607)
Error: Template '' specified in host definition could not be not found (config file '/usr/local/nagios/etc/hosttemplates.cfg', starting on line 758)
Error: Host escalation host name is NULL
Error: Could not register host escalation (config file '/usr/local/nagios/etc/hostescalations.cfg', starting on line 16)

Nagios Core 4.4.13
Copyright (c) 2009-present Nagios Core Development Team and Community Contributors
Copyright (c) 1999-2009 Ethan Galstad
Last Modified: 2023-06-01
License: GPL

Website: https://www.nagios.org
Reading configuration data...
Read main config file okay...
Error: Template '' specified in host definition could not be not found (config file '/usr/local/nagios/etc/hosttemplates.cfg', starting on line 607)
Error: Template '' specified in host definition could not be not found (config file '/usr/local/nagios/etc/hosttemplates.cfg', starting on line 758)
Error: Host escalation host name is NULL
Error: Could not register host escalation (config file '/usr/local/nagios/etc/hostescalations.cfg', starting on line 16)
Error processing object config files!

[danderson]

Thanks for reaching out @infofedsec,

Where was this error and could you attach the lines around line 607 and 758 in the /usr/local/nagios/etc/hosttemplates.cfg file if you don't mind?