diff --git a/lib/ash/actions/managed_relationships.ex b/lib/ash/actions/managed_relationships.ex
index be74b82d..37f6411e 100644
--- a/lib/ash/actions/managed_relationships.ex
+++ b/lib/ash/actions/managed_relationships.ex
@@ -443,7 +443,7 @@ defmodule Ash.Actions.ManagedRelationships do
               |> Ash.Changeset.add_error(
                 InvalidRelationship.exception(
                   relationship: relationship.name,
-                  message: "Changes would create a new related record"
+                  message: "changes would create a new related record"
                 )
               )
               |> Ash.Changeset.put_context(:private, %{
@@ -1082,7 +1082,7 @@ defmodule Ash.Actions.ManagedRelationships do
           {:error,
            InvalidRelationship.exception(
              relationship: relationship.name,
-             message: "Changes would create a new related record"
+             message: "changes would create a new related record"
            )}
         end
 
@@ -1236,7 +1236,7 @@ defmodule Ash.Actions.ManagedRelationships do
         {:error,
          InvalidRelationship.exception(
            relationship: relationship.name,
-           message: "Changes would update a record"
+           message: "changes would update a record"
          )}
 
       :ignore ->
@@ -1621,7 +1621,7 @@ defmodule Ash.Actions.ManagedRelationships do
              {:error,
               InvalidRelationship.exception(
                 relationship: relationship.name,
-                message: "Changes would destroy a record"
+                message: "changes would destroy a record"
               )}}
 
           {:unrelate, action_name} ->
diff --git a/lib/ash/actions/read.ex b/lib/ash/actions/read.ex
index 7dd39c22..93f7c16b 100644
--- a/lib/ash/actions/read.ex
+++ b/lib/ash/actions/read.ex
@@ -496,7 +496,7 @@ defmodule Ash.Actions.Read do
 
       %Ash.Query.Ref{attribute: %Ash.Resource.Calculation{}} = ref ->
         raise Ash.Error.Framework.AssumptionFailed,
-          message: "Unhandled calculation in filter statement #{inspect(ref)}"
+          message: "unhandled calculation in filter statement #{inspect(ref)}"
 
       %Ash.Query.Ref{attribute: %Ash.Query.Calculation{} = calc} = ref ->
         %{
@@ -1738,7 +1738,7 @@ defmodule Ash.Actions.Read do
           )
         else
           raise Ash.Error.Framework.AssumptionFailed,
-            message: "Only calculation & relationship deps should have input"
+            message: "only calculation & relationship deps should have input"
         end
 
       %Ash.Query.Calculation{} = calculation ->
@@ -1785,7 +1785,7 @@ defmodule Ash.Actions.Read do
           true ->
             raise Ash.Error.Framework.AssumptionFailed,
               message:
-                "Only attribute & aggregate deps should remain at this point. Got #{inspect(other)} on #{inspect(query.resource)}"
+                "only attribute & aggregate deps should remain at this point, got #{inspect(other)} on #{inspect(query.resource)}"
         end
     end)
   end
diff --git a/lib/ash/changeset/changeset.ex b/lib/ash/changeset/changeset.ex
index 9a922257..d371bafa 100644
--- a/lib/ash/changeset/changeset.ex
+++ b/lib/ash/changeset/changeset.ex
@@ -2625,7 +2625,7 @@ defmodule Ash.Changeset do
         error =
           InvalidRelationship.exception(
             relationship: relationship.name,
-            message: "Relationship is not editable"
+            message: "relationship is not editable"
           )
 
         add_error(changeset, error)
@@ -2634,7 +2634,7 @@ defmodule Ash.Changeset do
         error =
           InvalidRelationship.exception(
             relationship: relationship.name,
-            message: "Cannot manage a manual relationship"
+            message: "cannot manage a manual relationship"
           )
 
         add_error(changeset, error)
@@ -2643,7 +2643,7 @@ defmodule Ash.Changeset do
         error =
           InvalidRelationship.exception(
             relationship: relationship.name,
-            message: "Cannot manage a #{type} relationship with a list of records"
+            message: "cannot manage a #{type} relationship with a list of records"
           )
 
         add_error(changeset, error)
@@ -2707,7 +2707,7 @@ defmodule Ash.Changeset do
               changeset,
               InvalidRelationship.exception(
                 relationship: relationship.name,
-                message: "Cannot provide structs that don't match the destination"
+                message: "cannot provide structs that don't match the destination"
               )
             )
           else
diff --git a/lib/ash/error/changes/unknown_error.ex b/lib/ash/error/changes/unknown_error.ex
deleted file mode 100644
index 340eb5be..00000000
--- a/lib/ash/error/changes/unknown_error.ex
+++ /dev/null
@@ -1,16 +0,0 @@
-defmodule Ash.Error.Changes.UnknownError do
-  @moduledoc "Used when a change fails for an unknown reason"
-  use Ash.Error.Exception
-
-  def_ash_error([:field, :error], class: :invalid)
-
-  defimpl Ash.ErrorKind do
-    def id(_), do: Ash.UUID.generate()
-
-    def code(_), do: "unknown_change_error"
-
-    def message(%{field: field, error: error}) do
-      "Unknown error for change on field #{field}: #{inspect(error)}"
-    end
-  end
-end
diff --git a/lib/ash/error/forbidden/policy.ex b/lib/ash/error/forbidden/policy.ex
index 3e1d5b4f..c07a7c1d 100644
--- a/lib/ash/error/forbidden/policy.ex
+++ b/lib/ash/error/forbidden/policy.ex
@@ -407,6 +407,6 @@ defmodule Ash.Error.Forbidden.Policy do
       end
     end
 
-    def code(_), do: "forbidden"
+    def code(_), do: "forbidden_by_policy"
   end
 end
diff --git a/lib/ash/filter/filter.ex b/lib/ash/filter/filter.ex
index abb53993..d7fe5f38 100644
--- a/lib/ash/filter/filter.ex
+++ b/lib/ash/filter/filter.ex
@@ -2379,7 +2379,7 @@ defmodule Ash.Filter do
                InvalidFilterValue.exception(
                  value: inspect(nested_statement),
                  message:
-                   "A single value must be castable to the primary key of the resource: #{inspect(context.resource)}"
+                   "a single value must be castable to the primary key of the resource: #{inspect(context.resource)}"
                )}
           end
         end
@@ -2666,7 +2666,7 @@ defmodule Ash.Filter do
            Ash.Error.Query.InvalidExpression.exception(
              expression: expr,
              message:
-               "Cannot access multiple resources for a data layer that can't be joined from within a single expression"
+               "cannot access multiple resources for a data layer that can't be joined from within a single expression"
            )}
         end
 
@@ -2674,7 +2674,7 @@ defmodule Ash.Filter do
         {:error,
          Ash.Error.Query.InvalidExpression.exception(
            expression: expr,
-           message: "Cannot access multiple data layers within a single expression"
+           message: "cannot access multiple data layers within a single expression"
          )}
     end
   end
diff --git a/lib/ash/resource/change/relate_actor.ex b/lib/ash/resource/change/relate_actor.ex
index bfaaf4b8..61aacd6d 100644
--- a/lib/ash/resource/change/relate_actor.ex
+++ b/lib/ash/resource/change/relate_actor.ex
@@ -22,7 +22,7 @@ defmodule Ash.Resource.Change.RelateActor do
         changeset,
         InvalidRelationship.exception(
           relationship: opts[:relationship],
-          message: "Could not relate to actor, as no actor was found (and :allow_nil? is false)"
+          message: "could not relate to actor, as no actor was found (and :allow_nil? is false)"
         )
       )
     end
diff --git a/lib/ash/resource/validation/builtins.ex b/lib/ash/resource/validation/builtins.ex
index 378224aa..f327836a 100644
--- a/lib/ash/resource/validation/builtins.ex
+++ b/lib/ash/resource/validation/builtins.ex
@@ -179,7 +179,7 @@ defmodule Ash.Resource.Validation.Builtins do
 
       validate numericality(:age, greater_than_or_equal_to: 18),
         where: [attribute_equals(:show_adult_content, true)],
-        message: "Must be over %{greater_than_or_equal_to} to enable adult content."
+        message: "must be over %{greater_than_or_equal_to} to enable adult content."
 
       validate numericality(:points, greater_than: 0, less_than_or_equal_to: 100)
   """
diff --git a/lib/ash/resource/validation/confirm.ex b/lib/ash/resource/validation/confirm.ex
index 1d5597fe..8f305414 100644
--- a/lib/ash/resource/validation/confirm.ex
+++ b/lib/ash/resource/validation/confirm.ex
@@ -42,7 +42,7 @@ defmodule Ash.Resource.Validation.Confirm do
        InvalidAttribute.exception(
          field: opts[:confirmation],
          value: confirmation_value,
-         message: "Confirmation did not match value"
+         message: "confirmation did not match value"
        )}
     end
   end
diff --git a/lib/ash/resource/validation/string_length.ex b/lib/ash/resource/validation/string_length.ex
index 21f49b8b..c1be49f5 100644
--- a/lib/ash/resource/validation/string_length.ex
+++ b/lib/ash/resource/validation/string_length.ex
@@ -37,8 +37,7 @@ defmodule Ash.Resource.Validation.StringLength do
                InvalidAttribute.exception(
                  value: value,
                  field: opts[:attribute],
-                 message: "%{field} could not be parsed",
-                 vars: [field: opts[:attribute]]
+                 message: "could not be parsed"
                )}
           end
 
@@ -60,8 +59,8 @@ defmodule Ash.Resource.Validation.StringLength do
        InvalidAttribute.exception(
          value: value,
          field: opts[:attribute],
-         message: "%{field} must have length of exactly %{exact}",
-         vars: [field: opts[:attribute], exact: exact]
+         message: "must have length of exactly %{exact}",
+         vars: [exact: exact]
        )}
     end
   end
@@ -76,8 +75,8 @@ defmodule Ash.Resource.Validation.StringLength do
        InvalidAttribute.exception(
          value: value,
          field: opts[:attribute],
-         message: "%{field} must have length of between %{min} and %{max}",
-         vars: [field: opts[:attribute], min: min, max: max]
+         message: "must have length of between %{min} and %{max}",
+         vars: [min: min, max: max]
        )}
     end
   end
@@ -90,8 +89,8 @@ defmodule Ash.Resource.Validation.StringLength do
        InvalidAttribute.exception(
          value: value,
          field: opts[:attribute],
-         message: "%{field} must have length of at least %{min}",
-         vars: [field: opts[:attribute], min: min]
+         message: "must have length of at least %{min}",
+         vars: [min: min]
        )}
     end
   end
@@ -104,8 +103,8 @@ defmodule Ash.Resource.Validation.StringLength do
        InvalidAttribute.exception(
          value: value,
          field: opts[:attribute],
-         message: "%{field} must have length of no more than %{max}",
-         vars: [field: opts[:attribute], max: max]
+         message: "must have length of no more than %{max}",
+         vars: [max: max]
        )}
     end
   end
diff --git a/test/changeset/changeset_test.exs b/test/changeset/changeset_test.exs
index e4a5145b..5435db2e 100644
--- a/test/changeset/changeset_test.exs
+++ b/test/changeset/changeset_test.exs
@@ -519,7 +519,7 @@ defmodule Ash.Test.Changeset.ChangesetTest do
       post2 = %{title: "title"}
 
       assert_raise Ash.Error.Invalid,
-                   ~r/Invalid value provided for posts: Changes would create a new related record/,
+                   ~r/Invalid value provided for posts: changes would create a new related record/,
                    fn ->
                      Author
                      |> Changeset.new()
@@ -786,7 +786,7 @@ defmodule Ash.Test.Changeset.ChangesetTest do
         )
 
       assert [%Ash.Error.Changes.InvalidRelationship{} = relation_error] = changeset.errors
-      assert relation_error.message =~ "Cannot provide structs that don't match the destination"
+      assert relation_error.message =~ "cannot provide structs that don't match the destination"
     end
 
     test "it returns error if relationship does not exists" do
@@ -872,7 +872,7 @@ defmodule Ash.Test.Changeset.ChangesetTest do
     end
 
     test "arguments can be used in invalid changes" do
-      assert_raise Ash.Error.Invalid, ~r/Confirmation did not match value/, fn ->
+      assert_raise Ash.Error.Invalid, ~r/confirmation did not match value/, fn ->
         Category
         |> Changeset.new(%{"name" => "foo"})
         |> Changeset.set_argument(:confirm_name, "bar")
@@ -904,7 +904,7 @@ defmodule Ash.Test.Changeset.ChangesetTest do
                %Ash.Error.Changes.InvalidAttribute{
                  class: :invalid,
                  field: :confirm_name,
-                 message: "Confirmation did not match value",
+                 message: "confirmation did not match value",
                  path: []
                }
              ] =
diff --git a/test/resource/validation/string_length_test.exs b/test/resource/validation/string_length_test.exs
index a5c8078c..1be0be2f 100644
--- a/test/resource/validation/string_length_test.exs
+++ b/test/resource/validation/string_length_test.exs
@@ -25,7 +25,7 @@ defmodule Ash.Test.Resource.Validation.StringLengthTest do
       {:ok, opts} = StringLength.init(attribute: :body, min: 3)
       changeset = Ash.Changeset.new(Post, %{body: "no"})
 
-      assert_error(changeset, opts, "body must have length of at least 3")
+      assert_error(changeset, opts, "must have length of at least 3")
     end
   end
 
@@ -41,7 +41,7 @@ defmodule Ash.Test.Resource.Validation.StringLengthTest do
       {:ok, opts} = StringLength.init(attribute: :body, max: 3)
       changeset = Ash.Changeset.new(Post, %{body: "invalid"})
 
-      assert_error(changeset, opts, "body must have length of no more than 3")
+      assert_error(changeset, opts, "must have length of no more than 3")
     end
   end
 
@@ -57,10 +57,10 @@ defmodule Ash.Test.Resource.Validation.StringLengthTest do
       {:ok, opts} = StringLength.init(attribute: :body, exact: 3)
 
       changeset = Ash.Changeset.new(Post, %{body: "no"})
-      assert_error(changeset, opts, "body must have length of exactly 3")
+      assert_error(changeset, opts, "must have length of exactly 3")
 
       changeset = Ash.Changeset.new(Post, %{body: "invalid"})
-      assert_error(changeset, opts, "body must have length of exactly 3")
+      assert_error(changeset, opts, "must have length of exactly 3")
     end
   end
 
@@ -76,10 +76,10 @@ defmodule Ash.Test.Resource.Validation.StringLengthTest do
       {:ok, opts} = StringLength.init(attribute: :body, min: 2, max: 4)
 
       changeset = Ash.Changeset.new(Post, %{body: "n"})
-      assert_error(changeset, opts, "body must have length of between 2 and 4")
+      assert_error(changeset, opts, "must have length of between 2 and 4")
 
       changeset = Ash.Changeset.new(Post, %{body: "invalid"})
-      assert_error(changeset, opts, "body must have length of between 2 and 4")
+      assert_error(changeset, opts, "must have length of between 2 and 4")
     end
   end