I've installed your module to my website. But, when trying to add new coupon, I always get the following errors:
Fatal error: Call to undefined function mb_substr_count() in /public_html/sites/default/modules/uc_coupon/uc_coupon.module on line 293
What should I do to fix this problem?
FYI, I have uninstalled the previous version of this module and delete the table from database (I can only find the table that related to this module in the "System" Table) before installing the current version.
Thanks a bunch.