Bug in SQL Server provider when using UTF8 collations

I’ve encountered exceptions when using EF with SQL Server and configuring

• the database and all column collations to be a UTF8 collation and
• all columns to use varchar rather than nvarchar (as one should with UTF8 collations on SQL Server, somewhat counter-intuitively).

I’ve been doing this for a while now without obvious issues, but in a project that does some massive import of larger text portions some of the inserts fail with an exception:

SqlException: The incoming tabular data stream (TDS) remote procedure call (RPC) protocol stream is incorrect. Parameter 7 ("@p8"): Data type 0xA7 has an invalid data length or metadata length.

This does not happen with the traditional nvarchar type, and it happens only in some (thankfully reproducible) circumstances.

I have reduced my import to a test case. See instructions to reproduce there.

Version information

SQL Server version: Microsoft SQL Server Developer (64-bit) 16.0.1050.5 on Windows EF Core version: 6.0.16 Database provider: Microsoft.EntityFrameworkCore.SqlServer Target framework: .NET 6.0 Operating system: Windows 11 IDE: Visual Studio 2022 17.5.2

[jtheisen]

Make sure you got the right branch.

[JRahnama]

I am able to reproduce the issue. with the repro. I will get back to you on this.