When decompiling an enum and looking at it in IL, the whole type definitions of the underlying type are missing, the assignments are incorrect and there is a sort order issue (JustDecompile sorts according to the Name but should keep the original order how the elements have been compiled).

Current decompilation:

.class public auto ansi sealed Hafner.Testing.Enums.CharEnum
    extends [mscorlib]System.Enum
{
    Alpha = α
    Beta = β
    Chi = χ
    Delta = δ
    Epsilon = ϵ
    Eta = η
    Gamma = γ
    Iota = ι
    Kappa = κ
    Lambda = λ
    Mu = μ
    Nu = ν
    Omega = ω
    Omicron = o
    Phi = ϕ
    Pi = π
    Psi = ψ
    Rho = ρ
    Sigma = σ
    Tau = τ
    Theta = θ
    Upsilon = υ
    Xi = ξ
    Zeta = ζ
}

Expected decompilation:

.class public auto ansi sealed Hafner.Testing.Enums.CharEnum
       extends [mscorlib]System.Enum
{
	.field public specialname rtspecialname char value__
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Alpha = char(0x03B1)    //'α'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Beta = char(0x03B2)     //'β'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Gamma = char(0x03B3)    //'γ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Delta = char(0x03B4)    //'δ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Epsilon = char(0x03F5)  //'ϵ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Zeta = char(0x03B6)     //'ζ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Eta = char(0x03B7)      //'η'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Theta = char(0x03B8)    //'θ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Iota = char(0x03B9)     //'ι'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Kappa = char(0x03BA)    //'κ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Lambda = char(0x03BB)   //'λ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Mu = char(0x03BC)       //'μ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Nu = char(0x03BD)       //'ν'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Xi = char(0x03BE)       //'ξ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Omicron = char(0x006F)  //'o'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Pi = char(0x03C0)       //'π'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Rho = char(0x03C1)      //'ρ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Sigma = char(0x03C3)    //'σ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Tau = char(0x03C4)      //'τ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Upsilon = char(0x03C5)  //'υ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Phi = char(0x03D5)      //'ϕ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Chi = char(0x03C7)      //'χ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Psi = char(0x03C8)      //'ψ'
	.field public static literal valuetype Hafner.Testing.Enums.FlagsVanillaChar Omega = char(0x03C9)    //'ω'

}

The displayed IL code is not valid IL and lots of details are missing. It would be nice if that could be fixed. 
I attach a test DLL (still status 'work in progress') with different valid and invalid enum definitions on which you can try out any fixed code.
Best regards
Christoph