Excel interop loading XLLs and DLLs

Question

I have excel with the Bloomberg API ( which uses simple calls like =BDP(\"MS equity\",\"ask\") ). I also have a C# application that opens an excel file (through interop) tha

Answer 1

I realize that it's been while since this question has been asked. Nevertheless I want to share my experience as I came across the same problem. An easy solution is to proceed as suggested in https://blogs.msdn.microsoft.com/accelerating_things/2010/09/16/loading-excel-add-ins-at-runtime/ by first setting .Installed to false and then to true:

this._application = new Application
                {
                    EnableEvents = true,
                    Visible = true
                };

                //Load Bloomberg Add-In
                for (var i = 1; i <= this._application.AddIns.Count; i++)
                {
                    var currentAddIn = this._application.AddIns.Item[i];

                    if (currentAddIn.Name != "BloombergUI.xla") continue;

                    currentAddIn.Installed = false;
                    currentAddIn.Installed = true;
                }