You can get SQL Server Developer Edition for free by signing up at the Visual Stuido Dev Esentials website.  Info is here:
https://blogs.technet.microsoft.com/dataplatforminsider/2016/03/31/microsoft-sql-server-developer-edition-is-now-free/
Dev Esentials site which is also...

You probably want to check things like memory usage and PLE over time, instead of making knee-jerk reactions to what you see on one particular day.  It may be that...

Page Life Expectancy doesn't tell you how much memory is being used, just a rough idea of how long a page in memory stays in memory.  To see h ow...

I can't think of a reason why a special SQL aware backup application would be a must have.  There's plenty of free scripts available that people use for much larger...

an informative and fun series by Brent Ozar is "How to think like the SQL Server engine", available for free:
https://www.brentozar.com/training/think-like-sql-server-engine/

So if I understand, you've only converted the column in Dim_Date table, not the table actvt_dt is in?  If you want to join on those two columns, they should be...

Do you have backup compression turned on by default?  You can check that like this:
SELECT name, value_in_use...

I believe certain editions of Visual Studio have a schema comparison tool as well, I've always used the RedGate tool mentioned by BMG though.
https://www.visualstudio.com/vs/ssdt/

maybe it would be better to do this as a JOIN instead of a subquery:
UPDATE a SET
    OverrideNotes = b.OverrideNotes
  FROM rskgov.FraudOpsDashboardVettingDataYTD a
  INNER JOIN...

Given the complexity of the criteria of determining business days, this would probably be most easily solved if you had some kind of calendar table in your system.  A calendar...

What have you tried to resolve this?  The statistics don't look out of date, but you haven't actually given us the table and index definitions, or the execution plan.  We'd...

I'd check statistics first before worrying about index fragmentation.

SELECT SCHEMA_NAME(o.schema_id) AS SchemaName, o.name AS TableName, i.name AS IndexName,
    s.name AS StatsName, STATS_DATE(s.object_id, s.stats_id) AS StatsDate,

Is the connection actually getting to the database server and failing there?  The error you see on the .Net side is designed to be vague, you may get a better...