We have a problem when we are trying to get live view from Monitorsoft's Sentintel suite.The error we get is Directshow failure.Below you can see the final answer we got from their technical support.

MIP
, ,
1

“Thanks for checking that. This indicates it is the Milestone XML form sending the local IP rather than the NAT IP of the cameras. Unfortunately it must be the ARC or installer who contacts Milestone to reconfigure this, as we did not provide the DVR. You can tell them that a customer of ours spoke to a Milestone employee known as ‘Ed’ who resolved this for them in November last year.: “Ed from Milestone made configuration changes on the Milestone to correctly give the NAT address of the unit in the XML which is used for connecting to cameras”.”

2

This might be what “Ed” did.

https://supportcommunity.milestonesys.com/s/article/enable-public-access-in-XProtect-Corporate?language=en_US

As this does not pertain to development but to a general situation you will most likely get better help from the partners active in the Support Community - If my answer is not fulfilling please ask at - https://supportcommunity.milestonesys.com