In 3ds Max 2017, due to a bug introduced in MaxScript, PolyUnwrapper actions might be 50% slower than in previous 3ds Max versions.
There are some remaining UI issues in 3ds Max 2017 when UI scale is not 100%
Some Antivirus Software will flag PolyUnwrapper as a potential virus, which is a false positive. You can safely whitelist PolyUnwrapper in your Antivirus.
Editable Meshes will render all the triangles instead of polygons.
Hotkeys using Up and Down Arrows stop working when the UV Editor or a Rollout gets focus.
Undo does not restore Selection Pivot Position when Rotating, Scaling or Snapping.
Self-Illuminated Checker Texture might not display correctly in some cases.
For an unknown reason, sometimes the toolbar is disabled. If that happens, you need to unload and load PolyUnwrapper from the Utility panel.
Under certain conditions, you might experience a UI redraw issue in the UV Editor, when you open it.
Working with TeamViewer might produce a lag placing the PolyUnwrapper Toolbar, while moving/resizing the UV Editor.
If you are unable to view the .chm Help file, please have a look at this Microsoft KB917607.
You might also want to check if you have an option to unblock the file:
Right click on the .chm file and click on the [Unblock] button, under properties.