We received requests for a problem with certain screen resolutions, 12 inches for example, we reported these requests to the teams.
Some players seem to encounter problems to finish some puzzles (Krystal key for example).
It is important to check that your graphics card drivers are up to date with PC versions, please refer to the FAQs, check all the points of faq : Glitchs and graphic problems.
In the meantime more information we will do our best to propose solutions.
Thank you for your understanding.