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My applications had been running fine and I was doing various code changes and NuGet packages… then I was hit with this strange error, that did not even throw out a proper exception.

Microsoft.EntityFrameworkCore.DbUpdateException: An error occurred while saving the entity changes. See the inner exception for details.
—> Microsoft.Data.SqlClient.SqlException (0x80131904): Cannot insert explicit value for identity column in table ‘Books’ when IDENTITY_INSERT is set to OFF.
at Microsoft.Data.SqlClient.SqlCommand.<>c.b__211_0(Task1 result) at System.Threading.Tasks.ContinuationResultTaskFromResultTask2.InnerInvoke()

I’ve got the following code:

I have a challenge to convert Unicode character code like /u009a into the correct sign (/u009a => š). Example: u009a into š also i have html codes which need to be converted to the correct value like: &#263 => ć.

I need to create a COM class in .NET8 that needs to be accessible to Excel.