Kojo is acting wierd?
You probably have an incompatible JRE. There's more information about this on the the installation troubleshooting page.
Does Kojo have a log file where it logs any errors that it encounters?
Yes. It's located in the var/log directory, under your Kojo user directory (if you run Kojo and click on the Help -> About menuitem, you will see your Userdir right at the bottom of the About dialog).
My script does not run?
There could be a syntax error in your script. Look at the output pane to determine what the error is, fix it, and then rerun your script.
More information: when Kojo encounters a syntax error, it turns the right border of the script editor red, to give you immediate feedback that an error has occurred. The output window contains the error text (in red), and a hyperlink that takes you back to the line within the script editor where the error is located.
My script does not run, and I have no syntax errors in my script?
It's possible that a system error has occurred. The script editor right-border will be red, and there will be a message in the output window asking you to click on the red circle near the right edge of the Kojo status bar (which is at the bottom of the Kojo window). When you click on the circle, Kojo will give you more information about the problem. If you don't know what to do with this information, you are encouraged to report the problem on the support forum. But read on before doing that - some common problems are described.
After a system error (as described in the previous entry), clicking on the red circle in the status bar tells me that there has been a StackOverflowError?
You are probably making use of recursive functions. On some platforms (like 32 bit Linux), you hit the stack size limit earlier than on other platforms. You can easily fix this by adding -J-Xss1m to your Kojo default options.