Steps:

• Create a class that throws an exception in its constructor
• Use that class in an IClassFixture<>
• Run tests in the test class that defines the IClassFixture<>

Reproduction is here: https://github.com/thomhurst/xUnitFixtureDataErrorMessageReproduction

The error message implies that the data setup for the test is wrong, when in reality an exception was thrown.

Xunit.Sdk.TestClassException
The following constructor parameters did not have matching fixture data: MyData myData