I use the excellent Skia Sharp Graphics Library in order to support previewing Tiled maps on both PC and Mac versions of Tiled2Unity.

Unfortunately, some Windows users are experiencing issues with this library in their PC environment. To that end, Tiled2Unity 1.0.12.2 will disable previewing but still allow you to export Tiled maps to Unity project. It's not ideal, but it's better than crashing. :/

BTW, you can help me track down this bug for fixing. If you are not able to preview your map in Tiled2Unity then select all the text in your output directory and email it to me. (My email is found on my personal website at www.seanba.com)

Thanks!