C# – “Missing compiler required member” error being thrown multiple times with almost no changes to code

Here are the rules for how these functions work:

stringValue.CompareTo(otherStringValue)

1. null comes before a string
2. it uses CultureInfo.CurrentCulture.CompareInfo.Compare, which means it will use a culture-dependent comparison. This might mean that ß will compare equal to SS in Germany, or similar

stringValue.Equals(otherStringValue)

1. null is not considered equal to anything
2. unless you specify a StringComparison option, it will use what looks like a direct ordinal equality check, i.e. ß is not the same as SS, in any language or culture

stringValue == otherStringValue

1. Is not the same as stringValue.Equals().
2. The == operator calls the static Equals(string a, string b) method (which in turn goes to an internal EqualsHelper to do the comparison.
3. Calling .Equals() on a null string gets null reference exception, while on == does not.

Object.ReferenceEquals(stringValue, otherStringValue)

Just checks that references are the same, i.e. it isn't just two strings with the same contents, you're comparing a string object with itself.

Note that with the options above that use method calls, there are overloads with more options to specify how to compare.

My advice if you just want to check for equality is to make up your mind whether you want to use a culture-dependent comparison or not, and then use .CompareTo or .Equals, depending on the choice.

The .NET Assembly loader:

• is unable to find 1.2.0.203
• but did find a 1.2.0.200

This assembly does not match what was requested and therefore you get this error.

In simple words, it can't find the assembly that was referenced. Make sure it can find the right assembly by putting it in the GAC or in the application path. Also see https://docs.microsoft.com/archive/blogs/junfeng/the-located-assemblys-manifest-definition-with-name-xxx-dll-does-not-match-the-assembly-reference.