oraios/serena · error · FileNotFoundError

Memory {name} not found.

Error message

Memory {name} not found.

What it means

Raised by MemoryManager.edit_memory in src/serena/memories/memory_manager.py:397 when the memory file corresponding to the given name does not exist in the memories directory. Serena memories are stored as markdown files named after the sanitized memory name; editing requires the file to already exist (use save_memory/create to make a new one).

Source

Thrown at src/serena/memories/memory_manager.py:397

        regex_multiline: bool = True,
    ) -> str:
        """
        Edit a memory by replacing content matching a pattern.

        :param name: the memory name
        :param needle: the string or regex to search for
        :param repl: the replacement string
        :param mode: "literal" or "regex"
        :param allow_multiple_occurrences:
        :param is_tool_context: whether the call originates from a tool invocation (affects write-access checks)
        :param regex_multiline: whether to apply multi-line regex matching, enabling the flags re.DOTALL and re.MULTILINE
        """
        name = self._sanitize_name(name)
        self._check_not_ignored(name)
        self._check_write_access(name, is_tool_context)
        memory_file_path = self.get_memory_file_path(name)
        if not memory_file_path.exists():
            raise FileNotFoundError(f"Memory {name} not found.")
        with open(memory_file_path, encoding=self._encoding) as f:
            original_content = f.read()
        replacer = ContentReplacer(mode=mode, allow_multiple_occurrences=allow_multiple_occurrences, regex_multiline=regex_multiline)
        updated_content = replacer.replace(original_content, needle, repl)
        with open(memory_file_path, "w", encoding=self._encoding) as f:
            f.write(updated_content)
        return f"Memory {name} edited successfully."

    def validate_referential_integrity(
        self, include_unmarked: bool = True, include_fuzzy_matching: bool = True
    ) -> ReferentialIntegrityReport:
        """
        Validates referential integrity across this manager's memories.

        Thin wrapper around :meth:`MemoryReferenceAnalyzer.validate_referential_integrity`;
        see that method for the full description of behavior and parameters.
        """
        return MemoryReferenceAnalyzer(self).validate_referential_integrity(

View on GitHub (pinned to 7fcbca7e62)

Solutions

1. Run list_memories() and use an exact memory name from the result, respecting sanitization rules
2. Create the memory first with save_memory(name, ...) before editing it
3. Check the .serena/memories/ directory manually to confirm the file still exists

Example fix

// before
manager.edit_memory('architectur', needle='old', repl='new', mode='literal', allow_multiple_occurrences=False, is_tool_context=True)
// after
if 'architecture' in manager.list_memories().get_full_list():
    manager.edit_memory('architecture', needle='old', repl='new', mode='literal', allow_multiple_occurrences=False, is_tool_context=True)

if name not in manager.list_memories().get_full_list():
    raise LookupError(f'Memory {name} does not exist; create it first')

try:
    manager.edit_memory(name, needle, repl, mode='literal', allow_multiple_occurrences=False, is_tool_context=True)
except FileNotFoundError:
    manager.save_memory(name, default_content, is_tool_context=True)

When it happens

Trigger: Calling edit_memory (or the edit_memory tool) with a memory name that was never saved, a name that differs from the sanitized on-disk name, or one that was previously deleted or renamed.

Common situations: Agents referencing a memory from memory list output after manual deletion from the .serena/memories/ folder; typos or case mismatches in the memory name; calling edit before create in an automation script.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

• Context file not found: {path.resolve()}
• Project configuration file not found: {yaml_path}
• Serena configuration file not found: {config_file_path}
• Error: Path does not exist: {project_root}
• Error: Path is not a directory: {project_root}

AI-assisted analysis of oraios/serena@7fcbca7e62 (2026-08-29). Data as JSON: /api/errors/b61ba0bf38152c92. Report an issue: GitHub.