This may happen if the ISO country codes in the sales rights setting for the product are missing or incorrect.

To check the territories in which your product may be purchased using Glassboxx, go to Manage Books, and select the product you need to check. Scroll down to the Content/Country Rights section, where you will see the 2 character ISO country codes in which your products may may be purchased. Make any required changes to the country codes and click ‘Save’.

You can set the countries codes to ‘all countries’, by copy/pasting the following codes into the Sales Rights section:-

AF AL DZ AS AD AO AI AQ AG AR AM AW AU AT AZ BS BH BD BB BY BE BZ BJ BM BT BO BA BW BV BR IO VG BN BG BF BI KH CM CA CV KY CF TD CL CN CX CC CO KM CG CD CK CR HR CU CY CZ CI DK DJ DM DO EC EG SV GQ ER EE ET FK FO FJ FI FR GF PF TF GA GM GE DE GH GI GR GL GD GP GU GT GG GN GW GY HT HM HN HK HU IS IN ID IR IQ IE IM IL IT JM JP JE JO KZ KE KI KW KG LA LV LB LS LR LY LI LT LU MO MK MG MW MY MV ML MT MH MQ MR MU YT MX FM MD MC MN ME MS MA MZ MM NA NR NP NL AN NC NZ NI NE NG NU NF KP MP NO OM PK PW PS PA PG PY PE PH PN PL PT PR QA RO RU RW RE BL SH KN LC MF PM VC WS SM SA SN RS SC SL SG SK SI SB SO ZA GS KR ES LK SD SR SJ SZ SE CH SY ST TW TJ TZ TH TL TG TK TO TT TN TR TM TC TV UM VI UG UA AE GB US UY UZ VU VA VE VN WF EH YE ZM ZW AX