List of C# Compiler Warnings

Generally, you want to fix compiler warnings as they come up, but you may need to suppress some of them for legitimate reasons. A list of warnings and errors can be found here, but there’s no high-level list.
Here is a summarized list of warnings.

 

Warning	Description	More Info
Level 1 Warnings (Severe)
CS0420	‘identifier’: a reference to a volatile field will not be treated as volatile	https://msdn.microsoft.com/en-us/library/4bw5ewxy.aspx
CS0465	Introducing a ‘Finalize’ method can interfere with destructor invocation.	https://msdn.microsoft.com/en-us/library/02wtfwbt.aspx
CS1058	A previous catch clause already catches all exceptions	https://msdn.microsoft.com/en-us/library/ms228623.aspx
CS1060	Use of possibly unassigned field 'name'. Struct instance variables are initially unassigned if struct is unassigned.	https://msdn.microsoft.com/en-us/library/bb384216.aspx
CS1598	XML parser could not be loaded for the following reason: 'reason'. The XML documentation file 'file' will not be generated.	https://msdn.microsoft.com/en-us/library/szfbfb7e.aspx
CS1607	A warning was generated from the assembly-creation phase of the compilation.	https://msdn.microsoft.com/en-us/library/4a0640cd.aspx
CS1616	Option 'option' overrides attribute 'attribute' given in a source file or added module	https://msdn.microsoft.com/en-us/library/0b104xt8.aspx
CS1658	'warning text'. See also error 'error code' The compiler emits this warning when it overrides an error with a warning.	https://msdn.microsoft.com/en-US/library/ft0k10fs.aspx
CS1683	Reference to type 'Type Name' claims it is defined in this assembly, but it is not defined in source or any added modules	https://msdn.microsoft.com/en-US/library/6b351z64.aspx
CS1685	The predefined type 'System.type name' is defined in multiple assemblies in the global alias; using definition from 'File Name'	https://msdn.microsoft.com/en-us/library/8xys0hxk.aspx
CS1690	Accessing a member on 'member' may cause a runtime exception because it is a field of a marshal-by-reference class	https://msdn.microsoft.com/en-us/library/x524dkh4.aspx
CS1691	'number' is not a valid warning number	https://msdn.microsoft.com/en-us/library/7z6tx3wa.aspx
CS1699	Use command line option "compiler_option" or appropriate project settings instead of "attribute_name"	https://msdn.microsoft.com/en-us/library/xh3fc3x0.aspx
CS1762	A reference was created to embedded interop assembly '<assembly1>' because of an indirect reference to that assembly from assembly '<assembly2>'. Consider changing the 'Embed Interop Types' property on either assembly.	https://msdn.microsoft.com/en-us/library/ff183282.aspx
CS1956	Member 'name' implements interface member 'name' in type 'type'. There are multiple matches for the interface member at run-time. It is implementation dependent which method will be called.	https://msdn.microsoft.com/en-us/library/bb882526.aspx
CS3003	Type of 'variable' is not CLS-compliant	https://msdn.microsoft.com/en-us/library/ax5w23a6.aspx
CS3007	Overloaded method 'method' differing only by unnamed array types is not CLS-compliant	https://msdn.microsoft.com/en-us/library/3w1d36e0.aspx
CS3009	'type': base type 'type' is not CLS-compliant	https://msdn.microsoft.com/en-us/library/tdd79w48.aspx
CS4014	Because this call is not awaited, execution of the current method continues before the call is completed. Consider applying the 'await' operator to the result of the call.	https://msdn.microsoft.com/en-us/library/hh873131.aspx
Level 2 Warnings
CS0108	'member1' hides inherited member 'member2'. Use the new keyword if hiding was intended.	https://msdn.microsoft.com/en-US/library/3s8070fc.aspx
CS0467	Inherited members from different interfaces that have the same signature cause an ambiguity error.	https://msdn.microsoft.com/en-us/library/ms228509.aspx
CS0618	'member' is obsolete: 'text'	https://msdn.microsoft.com/en-us/library/x5ye6x1e.aspx
CS1701	Assuming assembly reference "Assembly Name #1" matches "Assembly Name #2", you may need to supply runtime policy	https://msdn.microsoft.com/en-us/library/2h4x8b08.aspx
Level 3 Warnings (Less Severe)
CS0675	Bitwise-or operator used on a sign-extended operand; consider casting to a smaller unsigned type first	https://msdn.microsoft.com/en-us/library/wdc6717a.aspx
CS1700	Assembly reference Assembly Name is invalid and cannot be resolved	https://msdn.microsoft.com/en-us/library/ac36c25f.aspx
Level 4 Warnings (Informational)
CS0429	Unreachable expression code detected	https://msdn.microsoft.com/en-us/library/2ch1a3w5.aspx
CS1591	Missing XML comment for publicly visible type or member 'Type_or_Member'	https://msdn.microsoft.com/en-us/library/zk18c1w9.aspx
CS1610	Unable to delete temporary file 'file' used for default Win32 resource -- resource	https://msdn.microsoft.com/en-US/library/z4aytccf.aspx