Paypal error

[SPD]

Customers who pay by paypal are getting this error at the end of making their payment, and not being returned to the website. Any ideas?

A General Script Error Occurred

Error: Bad input string = "SEQUENCE=3D3&ACTION=3DFinish&ORDERNUMBER=3DDW88TG90002053&REFPAGE=3Dhttp= %3a%2f%2fwww%2esmart%2dparts%2ddirect%2ecom%2facatalog%2fFilters%2ehtml&&= tx=3D15T06828GD754171P&st=3DCompleted&amt=3D6.75&cc=3DGBP&cm=3D&item_numb= er=3DDW88TG90002053&sig=3DI8bsubQBs51ZV4JB0VAHPlJYmzzkeipWOgxvZ3XtcLSQ7RS= p3qhRap1biHgAUdv36b5hCdl7DvyNBpOD%2fDRf7tnhKdGj2jNpaHuBQWUJ7etelc8r4cas2Q= Asrw35XeRAaJFquID31c7CquHmDMg5ktGiNINOSJ3FuTdI8OB9bc0%3d". Argument = count 22.=20
Press the Browser back button and try again or contact the site = owner.

[pinbrook]

1 search the forum using the error message as keywords to see if anyone else has encoutered and documented this issue

2 compact the database and refresh the website

3 read other posts on call back / paypal and check your palpay CP has set up the call back routine correctly