mIRC 7.33 (beta) and 7.34 (released today) introduced some changes to script processing, and as a result Invision will not function properly with it. As a temporary measure, please remain on mIRC v7.32 or earlier when using Invision. We will be looking into the changes, and will release an update to Invision that will be compatible with mIRC 7.34 when we can.
Please be patient, and have a great day!
Edit: A hotfix is now available to make Invision compatible -