I managed to identify the problem with my little experimentation.
Basically back then I thought of replacing the script calls of some of the content in Skills Examples to fit in my game. I replaced everything right until berserkersDance with my own skills. Without considering the other undefined script calls, I jumped right ahead to editing SkillTreesSystem.class2trees with those new script calls and so when I run the game and pressed F8 I found those undefined calls. I fixed it with replacing those unused skill script calls (by unused I mean every skill tree except class2trees) with null and now my game runs smooth. Now here comes the real problem: I can't get to add the contents on class2trees onto my character. In my game the beginning has your player actor (Actor 1, Class 1) select between 3 sprites. One of them is Warrior who upon interacting with the sprite it changes your class to Warrior (which is class 2). I can't get to load my one and only skill tree into the Skill Tree menu. At least I assume I was blind and I probably overlooked an error. Here's what it looks like.
My Attempt
1: skillTrees(10, [
skillTree('Class 1', 'Class 1', [
// Null represents empty square in the skill window.
// Arrow points from one skill to another.
null, null, null, wrathStrike, null, null, null,
null, null, null, arrowDown, null, null, null,
null, null, null, heroicStrike, null, null, null,
null, null, null, arrowDown, null, null, null,
null, null, null, secondWind, null, null, null,
null, null, arrowLeft, null, arrowRight, null, null,
null, cleave, null, null, null, bash, null,
null, null, null, null, null, null, null,
null, null, null, null, null, null, null,
]),
skillTree('Class 11', 'Class 11', [
null, null, null, null, null, null, null,
null, null, null, null, null, null, null,
null, null, null, null, null, null, null,
null, null, null, null, null, null, null,
null, null, null, null, null, null, null,
null, null, null, null, null, null, null,
null, null, null, null, null, null, null,
null, null, null, null, null, null, null,
null, null, null, null, null, null, null,
])]
),