Why did Arc Hydro stop working?

[RobertAnastasia]

I'm clearly not an expert but have been using Arc Hydro and Geo_HMS in Arcmap 10.4.1 fairly successfully for several years.  Last Friday (5/24) I suddenly started getting a new error message "System.Runtime.InteropServices.ComException (0x80004005): Error HRESULT E_FAIL has been returned from a call to a COM component at ESRI.ArcGIS.Geoprocessing.GeoProcessorClass.Execute(String Name, ..." in DEM reconditioning.  I looked up the available solutions online and none of them fixed the problem.  I tried old projects which had worked perfectly in the past and received the same error message.  Everything was fine on Thursday and DOA on Friday.  I couldn't imagine what I had done wrong.  I next upgraded to Arcmap 10.6.1 (adding all of the patches) but still got the same error.  I'm stuck.  My mistake should be so obvious that it's smacking me in the face but I can't see it.  Any thoughts?

[RobertAnastasia]

Yesterday I took my raw DEM and Agree Stream file to a local engineering firm and tried DEM Reconditioning on one of their computers.  It worked perfectly.  They are running ArcMap 10.4.1 in Windows 7.  I am running ArcMap 10.6.1 in Windows 10.  My Arc Hydro is the latest (10.6.0.44, dated 5/23/2019) version available.  It is beginning to look like this problem is related to a Windows 10 update that I received automatically precisely when the errors began.  It is already too late to recover the old version (you get 10 days) so I'll have to depend on ESRI to come up with a fix.  

[MichaelVolz]

Do you have access to a test computer where you can have IT people apply Windows updates to first to make sure nothing breaks before it negatively impacts your production environment?  This would help in future as damage has already been done.

Can you test workflow in Pro to see if you have the same issue?

[RobertAnastasia]

I'm a one man shop here with one computer.  Unfortunately, I am my own IT department (and am not really up to the task).  As far as I can figure it, all I can do at this point is turn off automatic Windows updates for now and install them and test them (one at a time) when I can.  If they create a problem, them I can run a Recovery, which is only available for 10 days after an update.