Seemingly random 404 errors on invoice download

[TeapotDan]

Hello,

 

I'm getting a seemingly random 404 error when trying to download invoice PDFs in the back office of a 1.6.1.2 site.

 

When I click on the 'download pdf' for invoices in the order page, sometimes it will work, other times it will 404 until I click another invoice to download and then go back to the original where it will download fine.

 

Has anyone experienced this? Or have a possible solution?

 

Thanks

[tuk66]

It looks like a server problem (overloading) - insufficient time or memory.