Incompatible script error can be caused by a number of things we will go in order of steps I use to try to solve these errors. Sometimes the error is just because the script is old or unsupported or it can be because of a problem with the automatic update code when these two issues have been ruled out the steps below should solve the problem.
1.When installing third party scripts donot use the playon automatic installer instead manually install scripts, to manually Install a script unzip the script or save the lua file to your desktop then go into playon and goto Plugins on the settings then look at the bottom you will see install and view click view then scripts and paste the lua file in there and restart playon.
2.Make sure you have the latest version of Playon installed this is common error when your playon is out of date.
3. Make sure you have the latest version of adobe flash player installed on your playon machine.
4.If you get this error on cable cutter makes sure you are not trying to install the full version on top of the sample* remove sample version first*.