blue iris has stopped working

If you are running BI as a service, first disable that option within the settings. Make you that you then close and restart the BI interface and then try upgrading.

If you are not running BI as a service then try enabling that option, again close and restart the BI interface and then try again.

was running BI as a service, tried your suggestion still crashes after upgrade
 
So installing even the next update from the one you have crashes BI?

At this point I would seriously consider making suitable backups of your license key, cam settings and blow the machine away.

Use the Microsoft media creation tool and reinstall Windows and then next install the latest version of BI to see what happens.
 
So installing even the next update from the one you have crashes BI?

At this point I would seriously consider making suitable backups of your license key, cam settings and blow the machine away.

Use the Microsoft media creation tool and reinstall Windows and then next install the latest version of BI to see what happens.

thats what its looking like, sent in to BI Support if they have any suggestions, if that does not help then format and reinstall windows and start over
 
if you have not already done this.
1) do a clean install of the latest version of bi
2) do not use your backup configuration. just manual add all camera and configurations.