https://sureai.net/forum/viewtopic.php?t=4604
[edit] MoveTo in Dialogue Result Script
Using MoveTo on the player in a dialogue result script triggers in a hidden bug that silently causes the player's viewing axis to be inverted. The player speaks to the NPC and the screen does a violent spinning motion on the viewport as they're zoomed in for dialogue. This is the only way you'll know that the bug has struck. If the player does not speak to another NPC before saving, then reloading that save will cause the game's viewport to be inverted. The ground will be on top, the sky on the bottom. Moving about becomes difficult or impossible. The affected savegame will probably not be salvageable. Do not use MoveTo in a dialogue result script. Instead, set variables in an NPC or quest script and use those variables to determine where your script should move the player.