Small bugfixes in exceptions

lark/exceptions.py

@@ -120,7 +120,8 @@ class UnexpectedInput(LarkError):
 
     def _format_expected(self, expected):
         if self._terminals_by_name:
-            expected = [self._terminals_by_name[t_name].user_repr() for t_name in expected]
+            d = self._terminals_by_name
+            expected = [d[t_name].user_repr() if t_name in d else t_name for t_name in expected]
         return "Expected one of: \n\t* %s\n" % '\n\t* '.join(expected)
 
 

lark/lark.py

@@ -265,7 +265,10 @@ class Lark(Serialize):
                 for name in (set(options) - _LOAD_ALLOWED_OPTIONS):
                     del options[name]
                 with FS.open(cache_fn, 'rb') as f:
-                    self._load(f, **options)
+                    try:
+                        self._load(f, **options)
+                    except Exception:
+                        raise RuntimeError("Failed to load Lark from cache: %r. Try to delete the file and run again." % cache_fn)
                 return
 
         if self.options.lexer == 'auto':