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IFFilesystem MCP Server on Windows throws 'Access denied - path outside allowed directories' or 'Parent directory does not exist' when operations target subdirectories of allowed paths.

THENEnsure the configured allowed path in mcp_config.json uses an uppercase drive letter (e.g., 'C:\...' not 'c:\...') and properly escapes backslashes (double backslashes). This works around a case-sensitivity bug in the server's path validation. Also note that find_by_name may work while read_file/list_directory fail; retry with uppercase path in the tool call.

IFFilesystem MCP Server on Windows returns 'Access denied - path outside allowed directories' when the drive letter in the path argument does not match the case used in the server configuration.

THENEnsure that the drive letter in the `mcp_config.json` path argument is uppercase (e.g., `C:\Users\...`). The server appears to canonicalize the allowed directory to uppercase, and lowercase drive letters in tool calls or config cause false positives. If the client (e.g., Cascade AI) sends lowercase paths, either normalize paths before calling or configure the server with uppercase and ensure the client also uses uppercase.

IFMCP Filesystem server on Windows rejects paths with lowercase drive letters, returning 'Access denied - path outside allowed directories' even when the path is within the allowed scope.

THENNormalize paths by converting drive letters to uppercase before comparison, or use case-insensitive string comparison for drive letters on Windows systems. Alternatively, ensure all provided paths use uppercase drive letters to avoid the false rejection.

IFFilesystem MCP server on Windows rejects paths with lowercase drive letters, returning 'Access denied - path outside allowed directories' error.

THENNormalize all paths by uppercasing the drive letter before comparison, or perform case-insensitive path comparison on Windows systems. This ensures that paths like 'g:\' and 'G:\' are treated equivalently.

IFUsing UNC paths (e.g., `\\server\share`) with the Filesystem MCP Server on Windows causes `list_directory` to succeed but `read_file` and other tools to fail with 'path outside allowed directories'.

THENMap the network share to a drive letter (e.g., `net use H: \\server\share`) and use the mapped drive letter in the server configuration. Avoid passing UNC paths directly to the server, as its internal path normalization does not handle UNC paths consistently across all tools.

IFFilesystem MCP server on Windows fails with 'Access denied - path outside allowed directories' when accessing subdirectories of the allowed path, even though the path is clearly within the allowed directory.

THENEnsure the allowed directory argument in the MCP server configuration uses an uppercase drive letter and double backslashes (e.g., 'C:\\Users\\...') to work around case-sensitivity and escaping bugs. As a temporary workaround, use the find_by_name tool for file discovery, as it may bypass the flawed validation.

IFWhen a path with a lowercase drive letter (e.g., 'g:\...') is used in a filesystem MCP server operation on Windows, the server rejects it as outside allowed directories.

THENNormalize paths to uppercase drive letters before validation, or perform a case-insensitive comparison for the drive letter portion on Windows systems. This ensures Windows case-insensitive path behavior is respected.