I added the behavior to delete the file before the record, here is my code:

<% 
' *** Delete File Before Delete Record 1.8.2
If (CStr(Request("MM_delete")) <> "" And CStr(Request("MM_recordId")) <> "") Then
  Dim DF_filesStr, DF_path, DF_suffix
  DF_filesStr = "storage_name"
  DF_path = "Session(\'Attachmentsfull\')"
  DF_suffix = ""
  DeleteFileBeforeRecord DF_filesStr,DF_path,MM_eimmigration_STRING,"dbo.Attachments","attachment_id",Request.Form("MM_recordId"),DF_suffix
end if
%>

The session is an absolute path, the database recod is deleted but not the actual file in the folder.

What may be wrong ?

I double checked and 'storage_name' is the exact name of the file in the folder.
and the absolute path to the file in the folder is: Session("Attachmentsfull"

Hello Alejandro,

this line:

 DF_path = "Session(\'Attachmentsfull\')" 

Must look like this instead:

 DF_path = Session("Attachmentsfull")  

Please, give it a try.

Regards.