Another email attachment question with Catalina beta

This script works fine with Mojave but does not attach the file when running on a machine with the latest Catalina beta.

Using Outlook 16.29, error message is: “Microsoft Outlook got an error: Can’t get file "Macintosh HD:Users:jdoe:Library:Application Support:MyApp:tmp:Customer No 1000 Ledger.pdf” of outgoing message id…

tell application “Microsoft Outlook”
activate
set strSUBJ to “Subject text”
set strCONTENT to “Body text”
set theMSG to make new outgoing message with properties {subject:strSUBJ, content:strCONTENT}
tell theMSG
make new to recipient with properties {email address:{name:“John Doe”, address:"jdoe@doemain.com"}}
make new attachment with properties {file:file"Macintosh HD:Users:jdoe:Library:Application Support:MyApp:tmp:Customer No 1000 Ledger.pdf"}
end tell
open theMSG
end tell

I’ve tried switching to a posix path but same error.

I’m wondering if it’s the file location but Apple Mail has no trouble attaching a file from there using a script, so???

Thanks for the help!