General Script Error After PayPal Payment

[nm-motorsport]

Customers are getting the following General Script Error after a paypal payment when it should redirect back to the site:

Error: Bad input string "SEQUENCE=3&ACTION=Finish&ORDERNUMBER=NM29DX90000552&REFPAGE=http%3a%2f%2fblinds4cars%2ecom%2facatalog%2fAlfa%2dRomeo%2dBrera%2dSun%2dBlinds%2ehtml&&PayerID=778WNDM3NZKUQ". Argument count 10.

I fixed this previously using an additional line of code in the OCCPayPalTemplate file as recommended in an old archived thread on here and it worked fine. However, today I made a small change to a product and refreshed my website and the error code started again. I have checked the OCCPayPalTemplate file and the extra line of code is still there.

Does anyone have any ideas?

[NormanRouxel]

That double ampersand ( html&&PayerID= ) looks wrong.

These argument pairs should be i.e. <something>=<some value>&<something else>=<another value>

Also, if you say you've made a change to a script, it would be a good idea to tell us what you've done.

[nm-motorsport]

The instructions that I took from an old thread are as below:

On the Merchant interface (logged in to www.paypal.com)

- go to 'Edit profile | Website payment preferences | Auto Return' and set to 'off'.

- Open the {Site Dir}\CommonOCC\OCCPayPalTemplate.pl with a text editor like notepad

- After line:
AddPostValues ('&', 'bn', 'ActinicCat_Cart_ST', $ALWAYS, $NOENCODE); # hard code the provider

- insert the following line:
AddPostValues ('&', 'rm', '2', $ALWAYS, $NOENCODE); # Set form send method to POST

- save the file and exit editor

'Upload' for your site and PayPal should now be properly configured.

This worked but as soon as any changes are made to the site and it is uploaded again, it stops working even though the code is still in place. After uploading a few times I got it to work only for it to stop working again after I needed to make a further amendment to the site and re-upload.