Attachment too large: file exceeds maximum allowed size

File size exceeds the ServiceNow instance's global attachment size limit configured in system properties (glide.attachment.max_size) (high likelihood)

Integration-specific attachment size limits are configured lower than the file being transferred through REST API or web service calls (high likelihood)

Target external system has attachment size restrictions that are smaller than ServiceNow's configured limits for outbound transfers (medium likelihood)

Table-specific attachment size limits are configured through business rules or ACLs that restrict certain record types to smaller file sizes (medium likelihood)

Load balancer or reverse proxy between systems is configured with HTTP request size limits that block large file transfers (low likelihood)

Step 1: Navigate to System Properties > System and check the glide.attachment.max_size property to verify the current global attachment size limit in bytes.

Step 2: Review the ECC Queue at System Import Sets > Administration > ECC Queue or integration logs to identify the exact file size that triggered the error.

Step 3: If the file size is legitimate, increase the glide.attachment.max_size system property value to accommodate larger files, considering storage and performance implications.

Step 4: Check for integration-specific size limits in REST API configurations, inbound web service properties, or custom scripted web services that may override global settings.

Step 5: Examine business rules on the target table (like Incident, Change Request) that might enforce attachment size restrictions through custom validation logic.

Step 6: For outbound integrations, verify the target system's attachment size limits and configure appropriate file compression or chunking in the integration logic.

Step 7: Test the integration again with a file just under the configured limit to confirm the settings are applied correctly.

Step 8: Monitor System Log at System Diagnostics > Log > Application Log for any additional errors related to attachment processing after making changes.