We run a multi-user ad tracking script from Alstrasoft (Ad Tracker Pro). The script has been running fine with no problems for several years on the same host. All of a sudden a problem started occuring. Existing users can no longer log in and new users complete the registration process but then cannot log in.
Everything else appears to be working fine, people can register, welcome emails are being sent but none of the log ins are working.
Need someone that can locate and repair the problem in a timely manner.