Download behavior is corrupting files

I have some download behaviors on a site which worked OK when I was using mySQL, but now that the site is running mySQLi it seems that the document encoding on Word, Excel files etc is becoming corrupted during the download process. The original files are fine and if I grab the uploaded files from the server, these are also fine. But when I use the download behavior to download the files, it will download OK but when I try to open it I either get an error message saying the file is corrupt and can't be opened, or it will attempt to open it but Word asks me to select the correct encoding and whatever type I choose, it won't open properly.

An example behavior would be:

<?php
WA_DFP_SetupDownloadStatusStruct("WA_DownloadResult1");
if(isset($_POST["download"]) || isset($_POST["download_x"])){
WA_DFP_DownloadFile("WA_DownloadResult1", "/downloads/", "".((isset($_POST["hiddenfield"]))?$_POST["hiddenfield"]:"") ."", "".((isset($_POST["hiddenname"]))?$_POST["hiddenname"]:"") ."", false, false, false, "", "", "", "");
}?>

<form method="post" action="" id="<?php echo $rsAppendicesIMPGI->getColumnVal("ID"); ?>" name="<?php echo $rsAppendicesIMPGI->getColumnVal("ID"); ?>">
<input name="hiddenfield" type="hidden" id="hiddenfield" value="<?php echo($rsAppendicesIMPGI->getColumnVal("Link")); ?>">
<input name="hiddenname" type="hidden" id="hiddenname" value="<?php echo($rsAppendicesIMPGI->getColumnVal("Title")); ?>">
<button type="submit" name="download" class="btn btn-primary"><i class="fal fa-download"></i></button>
</form>

I've attached an example of a downloaded file so that you can see what happens to it.

If you have a blank line of code before the download code that can cause the corruption. I'd need a copy of the page to track it down, but that is usually the issue when someone reports problems like this. The download code hasn't changed at all from Databridge v1 to v2 and it doesn't use MySQL code at all either, so that isn't the cause.

I'm guessing you have a blank line or other characters in the code on the page. If you want to give me FTP access I can help you track it down.

Hi Ray

I don't seem to have a blank line before the download behavior, FTP details are in the PM.

There are blank lines on line 2 and line 5 of test.php.

Removed the blank lines and it now works - thanks!