Bug #55643 Open it up and got this error
Submitted: 30 Jul 2010 3:36 Modified: 30 Aug 2010 3:48
Reporter: Jim DeKeyrel Email Updates:
Status: No Feedback Impact on me:
None 
Category:MySQL Server: General Severity:S3 (Non-critical)
Version: OS:Windows (Vista Bus)
Assigned to: CPU Architecture:Any

File: Maximum allowed size is 50MB.
Description:
Privacy:

If the data you need to attach is more than 50MB, you should create a compressed archive of the data, split it to 50MB chunks, and upload each of them as a separate attachment.

To split a large file: