Receiving error "Cannot write to C:\file.xlsx" when using Render tool for email attachment

[dchu]

I was wondering if anyone came across the following error when using the Render Tool to attach group specific email attachments?  I'm receiving an error in the Render tool saying "Cannot write to F:\xxxx\file.xslx"  However, when I tried to insert %TEMP% in front of the file name within the Formula tool, it worked fine but when it reached the Email Tool, it couldn't find the attachment.

I'm wondering why it would work for the first few attachments and not the subsequent ones.

Screenshot of workflow

Screenshot of error msg

Screenshot of formula tool

Screenshot of Render Tool

Screenshot of Email Tool

[dchu]

Never mind, I figured it out with another approach.  Still curious why the original flow didn't work though.