Are you referring to this?

Add TrustServerCertificate=True; to the connection string.

hmmmm.....

ISNULL(
    SUM(
        CASE 
            WHEN colB...

you ran this?

ISNULL(

SUM(

colA * Constant1 * colC /

(NULLIF(colB, 0) * CASE WHEN colD = 'XX' THEN Constant2 ELSE 1 END)

), 0

) AS calcdfield

Are you making any calculations in the report?

Try this:

ISNULL(
    SUM(
        colA * Constant1 * colC /
        (NULLIF(colB,...

Visual Studio: You can't delete from the report. In Report Designer, go to Solutions Explorer and delete from the Shared Dataset Folder or the Shared Data Sources...

Specify the Columns your want avoid using Select *.  Do you need all records returned? maybe use where clause to limit records.

in SSIS adjust  CommandTimeOut  set...

I'm not sure what your issue is? Is it timing out? or giving you an error?  Make a copy of you two views as a backup, just in case.

Does your...

I would think your problem is going to be a field where you are doing a calculation,  also look at if your are grouping with totals.

You can also disable report caching.

https://iatric.com/ssrs-tip-adding-a-tool-to-clear-the-ssrs-data-cache/

Connect to Report server in SSMS .

DELETE FROM ReportServerTempDB.dbo.ExecutionCache

Restart SSRS Services

Check connection string:

Sql Connection: Data Source=ServerName;Initial Catalog=DatabaseName;User ID=Username;Password=Password;

VS

OleDbConnection: Provider=SQLOLEDB;Data Source=ServerName;Initial Catalog=DatabaseName;User ID=Username;Password=Password;

If you're using SqlConnection in .NET, the connection string should not...

What are the prerequisites?