Salesforce Error 'Maximum size of request reached' When Importing Attachment or Content

Cause

The Salesforce API enforces a maximum batch size of approximately 50 MB (52,428,800 bytes) per batch when importing Attachment or Content records via Data Loader. If a single batch's combined file size exceeds this limit, the import fails with the error:

'Maximum size of request reached. Maximum size of request is 52428800 bytes.

Resolution

To resolve this error, choose one of the following options:

Option 1: Reduce Batch Size

In Data Loader Settings, set the batch size to 1. This ensures each batch contains a single record and avoids exceeding the 50 MB limit. 

Option 2: Reduce File Size

Split your import file into smaller files, each with a total content size below 50 MB. For more information on configuring batch size, see Configure Data Loader (link in Additional Resources).