# HTTP Error Codes > **NOTE** > > This topic describes only module-specific error codes. For details about universal error codes, see [Universal Error Codes](../errorcode-universal.md). ## 2300001 Protocol Not Supported **Error Message** Unsupported protocol. **Description** This error code is reported if the input protocol version is not supported by the server. **Cause** The input protocol version is not supported by the server. **Solution** Specify a protocol version supported by the server. ## 2300003 Incorrect URL Format **Error Message** Invalid URL format or missing URL. **Description** This error code is reported if the URL format is incorrect. **Cause** The format of the input URL is incorrect. **Solution** Specify a URL of the correct format. ## 2300005 Failed to Resolve the Domain Name of the Proxy Server **Error Message** Failed to resolve the proxy name. **Description** This error code is reported if the domain name of the proxy server cannot be resolved. **Cause** This error code is reported if the URL of the proxy server is incorrect. **Solution** Specify a URL of the correct format. ## 2300006 Failed to Resolve the Domain Name of the Host **Error Message** Failed to resolve the host name. **Description** This error code is reported if the domain name of the host cannot be resolved. **Cause** 1. The input URL is incorrect. 2. The network connection is abnormal. **Solution** 1. Specify a URL of the correct format. 2. Rectify network connection faults. ## 2300007 Failed to Connect to the Server **Error Message** Failed to connect to the server. **Description** This error code is reported if the server connection failed. **Cause** The format of the input URL is incorrect. **Solution** Specify a URL of the correct format. ## 2300008 Invalid Data Returned by the Server **Error Message** Invalid server response. **Description** This error code is reported if the data returned by the server is invalid. **Cause** The server encounters an error and returns data in non-HTTP format. **Solution** Check the server implementation. ## 2300009 Access to Remote Resources Denied **Error Message** Access to the remote resource denied. **Description** This error code is reported if the access to remote resources is denied by the server. **Cause** The access to the specified resource is denied by the server. **Solution** Check whether access to the requested resource is allowed. ## 2300016 HTT2 Framing Layer Error **Error Message** Error in the HTTP2 framing layer. **Description** This error code is reported if an error occurs on the HTTP2 framing layer. **Cause** HTTP2 is not supported by the server. **Solution** Capture and analyze packets to check whether HTTP2 is supported by the server. ## 2300018 Incomplete Data Returned by the Server **Error Message** Transferred a partial file. **Description** This error code is reported if data returned by the server is incomplete. **Cause** This problem is probable due to server implementation. **Solution** Check the server implementation. ## 2300023 Failed to Write Received Data to a Disk or Application **Error Message** Failed to write the received data to the disk or application. **Description** This error code is reported if an error occurs while writing received data to the disk or application. **Cause** - The application does not have the permission to write files or the file to be downloaded exceeds 5 MB. - The **destroy** function is called before the data of the last request is fully received. **Solution** Check the application permission and the size of the file to be downloaded. ## 2300025 Failed to Upload Data **Error Message** Upload failed. **Description** This error code is reported if data upload fails. **Cause** The file is too large or the network is faulty. The server may reject the **STOR** command if FTP is used. **Solution** Check the file size and network status. ## 2300026 Failed to Open or Read Local Data from a File or Application **Error Message** Failed to open or read local data from the file or application. **Description** This error code is reported if an error occurs while opening or reading local data from a file or application. **Cause** The application does not have the data read permission. **Solution** Check the permissions granted to the application. ## 2300027 Insufficient Memory **Error Message** Out of memory. **Description** This error code is reported if the memory is insufficient. **Cause** This error code is reported if the memory is insufficient. **Solution** Check the system memory. ## 2300028 Operation Timeout **Error Message** Operation timeout. **Description** This error code is reported if the operation times out. **Cause** The TCP connection or the read/write operation times out. **Solution** Check whether the network is stable and the signal strength is strong. If the network is normal, check whether the server is overloaded or service processing is slow. ## 2300047 Maximum Redirections Reached **Error Message** The number of redirections reaches the maximum allowed. **Description** This error code is reported if the number of redirections reaches the maximum. **Cause** Redirection is performed too frequently. **Solution** Check the server implementation. ## 2300052 No Content Returned by the Server **Error Message** The server returned nothing (no header or data). **Description** This error code is reported if no content is returned by the server. **Cause** This problem is probable due to server implementation. **Solution** Check the server implementation. ## 2300055 Failed to Send Network Data **Error Message** Failed to send data to the peer. **Description** This error code is reported if an error occurs while sending network data to the peer end. **Cause** This problem is probable due to a network fault. **Solution** Rectify network faults. ## 2300056 Failed to Receive Network Data **Error Message** Failed to receive data from the peer. **Description** This error code is reported if an error occurs while receiving network data from the peer end. **Cause** This problem is probable due to a network fault. **Solution** Rectify network faults. ## 2300058 Local SSL Certificate Error **Error Message** Local SSL certificate error. **Description** This error code is reported if the local SSL certificate is incorrect. **Cause** The format of the SSL certificate is incorrect. **Solution** Check the format of the SSL certificate. ## 2300059 Failed to Use the Specified SSL Cipher Algorithm **Error Message** The specified SSL cipher cannot be used. **Description** This error code is reported if the specified SSL cipher algorithm cannot be used. **Cause** The system does not support the cipher algorithm negotiated between the client and server. **Solution** Capture and analyze packets to check whether the cipher algorithm is supported. ## 2300060 Incorrect SSL Certificate or SSH Key of the Remote Server **Error Message** Invalid SSL peer certificate or SSH remote key. **Description** This error code is reported if the SSL certificate or SSH key of the remote server is incorrect. **Cause** It is probable that the server identity verification fails because the certificate has expired. **Solution** Check whether the certificate is valid. ## 2300061 Unrecognized or Incorrect HTTP Encoding Format **Error Message** Invalid HTTP encoding format. **Description** This error code is reported if the HTTP encoding format cannot be identified or is incorrect. **Cause** The HTTP encoding format is incorrect. **Solution** Check the server implementation. Currently, only gzip encoding is supported. ## 2300063 Maximum File Size Exceeded **Error Message** Maximum file size exceeded. **Description** This error code is reported if the maximum file size is exceeded. **Cause** The downloaded file is too large. **Solution** Check the server implementation. ## 2300070 Insufficient Server Disk Space **Error Message** Remote disk full. **Description** This error code is reported if the server disk space is insufficient. **Cause** The server disk is full. **Solution** Check the server disk space. ## 2300073 Uploaded File Already Exists **Error Message** Remote file already exists. **Description** This error code is reported if the server finds that the uploaded file already exists. **Cause** The uploaded file already exists. **Solution** Check the server for files that already exist. ## 2300077 No SSL CA Certificate or Access Permission **Error Message** The SSL CA certificate does not exist or is unaccessible. **Description** This error code is reported if the SSL CA certificate does not exist or the access permission is not available. **Cause** The SSL CA certificate is not available or the access permission is not granted. **Solution** Check whether the SSL CA certificate exists or the access permission is granted. ## 2300078 URL Requested File Not Found **Error Message** Remote file not found. **Description** This error code is reported if the file requested by the specified URL does not exist. **Cause** The file requested by the specified URL does not exist. **Solution** Check whether the file requested by the specified URL exists. ## 2300094 Identity Verification Failed **Error Message** Authentication error. **Description** This error code is reported if identity verification fails. **Cause** The specified identity verification field does not match that on the server. **Solution** Check whether the specified identity verification field matches that on the server. ## 2300998 Domain Access Denied **Error Message** It is not allowed to access this domain. **Description** This error code is reported if access to a certain domain is prohibited. **Cause** An incorrect server domain name is configured for the atomic service. **Solution** Configure a correct server domain name for the atomic service. ## 2300999 Unknown Error **Error Message** Unknown error. **Description** This error code is reported if an unknown error occurs. **Cause** An unknown error occurs. **Solution** Try again or contact technical support.