diff --git a/pooltool/physics/resolve/resolver.py b/pooltool/physics/resolve/resolver.py
index dcfe43e6..e496dda1 100644
--- a/pooltool/physics/resolve/resolver.py
+++ b/pooltool/physics/resolve/resolver.py
@@ -2,10 +2,13 @@
 
 from __future__ import annotations
 
+import shutil
+import traceback
 from pathlib import Path
 from typing import Optional
 
 import attrs
+from cattrs.errors import ClassValidationError
 
 import pooltool.user_config
 from pooltool.events.datatypes import AgentType, Event, EventType
@@ -120,40 +123,60 @@ def load(cls, path: Pathish) -> Resolver:
     @classmethod
     def default(cls) -> Resolver:
         """Load ~/.config/pooltool/physics/resolver.yaml if exists, create otherwise"""
-        if RESOLVER_PATH.exists():
-            resolver = cls.load(RESOLVER_PATH)
 
-            if resolver.version == VERSION:
-                return resolver
-            else:
-                run.info_single(
-                    f"{RESOLVER_PATH} is has version {resolver.version}, which is not up to "
-                    f"date with the most current version: {VERSION}. It will be replaced with the "
-                    f"default."
-                )
-
-        resolver = cls(
-            ball_ball=FrictionalMathavan(
-                friction=AlciatoreBallBallFriction(
-                    a=0.009951,
-                    b=0.108,
-                    c=1.088,
+        def _default_config():
+            return cls(
+                ball_ball=FrictionalMathavan(
+                    friction=AlciatoreBallBallFriction(
+                        a=0.009951,
+                        b=0.108,
+                        c=1.088,
+                    ),
+                    num_iterations=1000,
+                ),
+                ball_linear_cushion=Han2005Linear(),
+                ball_circular_cushion=Han2005Circular(),
+                ball_pocket=CanonicalBallPocket(),
+                stick_ball=InstantaneousPoint(
+                    english_throttle=1.0,
+                    squirt_throttle=1.0,
                 ),
-                num_iterations=1000,
-            ),
-            ball_linear_cushion=Han2005Linear(),
-            ball_circular_cushion=Han2005Circular(),
-            ball_pocket=CanonicalBallPocket(),
-            stick_ball=InstantaneousPoint(
-                english_throttle=1.0,
-                squirt_throttle=1.0,
-            ),
-            transition=CanonicalTransition(),
-            version=VERSION,
-        )
-
-        resolver.save(RESOLVER_PATH)
-        return resolver
+                transition=CanonicalTransition(),
+                version=VERSION,
+            )
+
+        if not RESOLVER_PATH.exists():
+            resolver = _default_config()
+            resolver.save(RESOLVER_PATH)
+            return resolver
+
+        try:
+            resolver = cls.load(RESOLVER_PATH)
+        except ClassValidationError:
+            full_traceback = traceback.format_exc()
+            dump_path = RESOLVER_PATH.parent / f".{RESOLVER_PATH.name}"
+            run.info_single(
+                f"{RESOLVER_PATH} is malformed and can't be loaded. It is being "
+                f"replaced with a default working version. Your version has been moved to "
+                f"{dump_path} if you want to diagnose it. Here is the error:\n{full_traceback}"
+            )
+            shutil.move(RESOLVER_PATH, dump_path)
+            resolver = _default_config()
+            resolver.save(RESOLVER_PATH)
+
+        if resolver.version == VERSION:
+            return resolver
+        else:
+            dump_path = RESOLVER_PATH.parent / f".{RESOLVER_PATH.name}"
+            run.info_single(
+                f"{RESOLVER_PATH} is has version {resolver.version}, which is not up to "
+                f"date with the most current version: {VERSION}. It will be replaced with the "
+                f"default. Your version has been moved to {dump_path}."
+            )
+            shutil.move(RESOLVER_PATH, dump_path)
+            resolver = _default_config()
+            resolver.save(RESOLVER_PATH)
+            return resolver
 
 
 def _snapshot_initial(shot: System, event: Event) -> None: