If you see this error, it means that you don't have a Vulkan driver in your system, or there's something wrong with it. Vulkan is the graphics programming interface that Tiny Glade uses. It's similar to Direct3D.
Please check Tiny Glade's hardware requirements. TL;DR: if you have >= 2GB of video memory, a GeForce GTX from the last decade, a Radeon from the last decade, or an Intel chip from the last four years, your hardware is probably okay. If unsure, consult the minimal requirements on our Steam page.
You can find some basic information about your graphics card in the TechPowerUp GPU Database. Take note if Vulkan is listed in the "Graphics Features" section. If the field says "N/A" or lists a value lower than "1.2", you might be out of luck.
If you have a modern NVIDIA card, you may still see this error if you also happen to have an AMD CPU. Sometimes Windows comes with extremely outdated drivers that mess things up.
Installing AMD drivers for the integrated graphics chip of your AMD CPU should help in this case: https://www.amd.com/en/support/download/drivers.html
We've also heard reports of some players overcoming this issue by using the "Launch Vulkan extension settings" option when starting Tiny Glade via Steam, selecting "NVIDIA" among the tick boxes on the configuration screen, and saving the setting via the "OK" button at the bottom.
Please note that NVIDIA have dropped support for mobile GPUs based on the "Kepler" architecture sooner than for non-mobile versions. This includes for example GeForce GT 740M and GeForce GTX 880M. While Vulkan drivers exist for them, they're outdated by many years, and don't support the features that Tiny Glade needs to work. The oldest driver that we've verified to work is 472.12 - if this driver (or newer) is not available for your graphics card, Tiny Glade will not work.
The oldest Intel chips that can launch Tiny Glade come with 6th generation Intel processors. You can find the drivers here. Please note that those chips will run Tiny Glade poorly.
Intel never released Vulkan drivers for chips older than that, so Tiny Glade will not work on Intel HD Graphics 500 series, HD Graphics 5000 series, HD Graphics 6000 series, or HD Graphics 4000 series or older.