Common bug:
The file upload is not required and a required text upload is also not required (check this if you are still not able to require the file upload). The item is simply added to the basket despite the text upload/file upload being required.

Possible Cause:
Missing database entries (not sure what causes this).

Solution:
-> Backup your database
-> Check that the following lines are missing from your database
-> Use "Admin->Tools->Install SQL Patches" to install the missing lines.

PHP Code:
INSERT INTO `configurationVALUES ('''Product option type Select''PRODUCTS_OPTIONS_TYPE_SELECT''0''The number representing the Select type of product option.'0NULL'2007-03-19 17:57:39''2007-03-19 17:57:39'NULLNULL);
INSERT INTO `configurationVALUES ('''Upload prefix''UPLOAD_PREFIX''upload_''Prefix used to differentiate between upload options and other options'0NULL'2007-03-19 17:57:39''2007-03-19 17:57:39'NULLNULL);
INSERT INTO `configurationVALUES ('''Text prefix''TEXT_PREFIX''txt_''Prefix used to differentiate between text option values and other option values'0NULL'2007-03-19 17:57:39''2007-03-19 17:57:39'NULLNULL);
INSERT INTO `configurationVALUES ('''Image Handler Version''IH_VERSION''2.0''This is used by image handler to check if the database is up to date with uploaded image handler files.'0100NULL'2007-06-06 16:47:03'NULL'zen_cfg_textarea_small('
Thank you to grantc for this fix.

Original post:
http://www.zen-cart.com/forum/showpo...3&postcount=20