typo fix

tests/service/data/TestTP/ProvidedTypes.fs

@@ -8993,7 +8993,7 @@ namespace ProviderImplementation.ProvidedTypes
                     if i < 0 then 
                         let msg =
                             if toTgt then sprintf "The design-time type '%O' utilized by a type provider was not found in the target reference assembly set '%A'. You may be referencing a profile which contains fewer types than those needed by the type provider you are using." t (getTargetAssemblies() |> Seq.toList)
-                            elif getSourceAssemblies() |> Seq.isEmpty then sprintf "A failure occured while determining compilation references"
+                            elif getSourceAssemblies() |> Seq.isEmpty then sprintf "A failure occurred while determining compilation references"
                             else sprintf "The target type '%O' utilized by a type provider was not found in the design-time assembly set '%A'. Please report this problem to the project site for the type provider." t (getSourceAssemblies() |> Seq.toList)
                         failwith msg
                     else