This will occur when you use Digital File Pro on an ASP Page.
After uploading a file, the generic request collection cannot be used.
If the MM_update variable is a querystong variable, you can use:
if (String(Request.Querystring("MM_update")) == "WAATKUpdateForm") {
if it is a form variable you can use:
if (String(WA_DFP_UploadObj.Form("MM_update")) == "WAATKUpdateForm") {
But make sure that the code to upload the file is before this code.