Backend Errors

In case of an error in a backend request, the Admin Service returns an appropriate 4xx or 5xx HTTP status code as well as the following HTTP headers in its response:

x-error: the English error message
x-error-code: the error code

Each error code maps to a template, which a client can use to process the English error message, for example to translate it into the user’s preferred language or adapt the error message to the context it occurred in.

Error Codes and Templates

Code	Template	Likely Root Cause
`AEM_BACKEND_FETCH_FAILED`	`Unable to fetch '$1' from '$2': $3`	Backend fetch failed (network, permissions, server error).
`AEM_BACKEND_NOT_FOUND`	`Unable to preview '$1': File not found`	Source document is missing or inaccessible.
`AEM_BACKEND_TYPE_UNSUPPORTED`	`Unable to preview '$1': File type not supported: $2`	File type not supported by the preview system.
`AEM_BACKEND_NO_HANDLER`	`Unable to preview '$1': No handler found for document: $2`	No processing handler available for this file type.
`AEM_BACKEND_NON_MATCHING_MEDIA`	`Unable to preview '$1': content is not a '$2' but: $3`	Actual media type does not match expected type.
`AEM_BACKEND_VALIDATION_FAILED`	`Unable to preview '$1': validation failed: $2`	Document failed backend validation checks.
`AEM_BACKEND_DOC_IMAGE_TOO_BIG`	`Unable to preview '$1': source contains large image: $2`	Embedded image inside a doc exceeds size limits.
`AEM_BACKEND_UNSUPPORTED_MEDIA`	`Unable to preview '$1': '$2' backend does not support file type.`	Specific backend does not support this media type.
`AEM_BACKEND_NO_CONTENT_TYPE`	`Unable to preview '$1': Content type header is missing`	Source response missing Content-Type header.
`AEM_BACKEND_JSON_INVALID`	`Unable to preview '$1': JSON fetched from markup is invalid: $2`	Markup contains malformed JSON.
`AEM_BACKEND_FILE_EMPTY`	`Unable to preview '$1': File is empty, no markdown version available`	Source file is empty.
`AEM_BACKEND_FILE_TOO_BIG`	`Unable to preview '$1': Documents larger than 100mb not supported: $2`	File exceeds 100 MB size limit.
`AEM_BACKEND_MP4_PARSING_FAILED`	`Unable to preview '$1': Unable to parse MP4`	MP4 file corrupted or unparseable.
`AEM_BACKEND_MP4_TOO_LONG`	`Unable to preview '$1': MP4 is longer than 2 minutes: $2`	MP4 exceeds duration limit.
`AEM_BACKEND_MP4_BIT_RATE_TOO_HIGH`	`Unable to preview '$1': MP4 has a higher bitrate than 300 KB/s: $2`	MP4 exceeds bitrate threshold.
`AEM_BACKEND_ICO_TOO_BIG`	`Unable to preview '$1': ICO is larger than 16KB: $2`	ICO exceeds maximum size.
`AEM_BACKEND_PDF_TOO_BIG`	`Unable to preview '$1': PDF is larger than 10MB: $2`	PDF exceeds size limit.
`AEM_BACKEND_SVG_SCRIPTING_DETECTED`	`Unable to preview '$1': Script or event handler detected in SVG at: $2`	Disallowed script/event attributes in SVG.
`AEM_BACKEND_SVG_ROOT_ITEM_MISSING`	`Unable to preview '$1': Expected XML content with an SVG root item`	SVG missing <svg> root element.
`AEM_BACKEND_SVG_PARSING_FAILED`	`Unable to preview '$1': Unable to parse SVG XML`	SVG XML is invalid or corrupted.
`AEM_BACKEND_SVG_TOO_BIG`	`Unable to preview '$1': SVG is larger than 20KB: $2`	SVG file exceeds size limit.
`AEM_BACKEND_IMAGE_TOO_BIG`	`Unable to preview '$1': Image is larger than $2: $3`	Image exceeds supported dimensions/size.
`AEM_BACKEND_CONFIG_EXISTS`	`Config already exists`	Attempted to create a config that already exists.
`AEM_BACKEND_CONFIG_TYPE_MISSING`	`No '$1' config in body or bad content type`	Config type missing from request or wrong content type.
`AEM_BACKEND_CONFIG_TYPE_INVALID`	`Bad '$1' config: $2`	Invalid or malformed config type/value.
`AEM_BACKEND_CONFIG_MISSING`	`Config not found`	Requested config does not exist.
`AEM_BACKEND_CONFIG_READ`	`Error reading config: $1`	Config read operation failed.
`AEM_BACKEND_CONFIG_CREATE`	`Error creating config: $1`	Config creation operation failed.
`AEM_BACKEND_CONFIG_UPDATE`	`Error updating config: $1`	Config update operation failed.
`AEM_BACKEND_CONFIG_DELETE`	`Error removing config: $1`	Config deletion operation failed.