You can use the technique in the topic
armory trick in act 1 to get through the wall to speak to the instructor, though I don't recall the exact sequence there (and without the teleporter pyramids in act 4, you'd have to repeat the process to get out again).
If that doesn't work, you can move the instructor back into the main room:
Teleporting anywhere (via hex editor).
If you zip your latest save (or just the data.000 file) and email it to support@larian.com, I can edit it for you.
Each save is a folder in the '..\SteamApps\common\beyond_divinity\savegames' folder (or similarly for the GOG install folder path).
In Windows Explorer you can zip a file or folder by right clicking on it/them and selecting 'Send To | Compressed (zipped) Folder'.
