Debugging is a significant part of a Quest Editor's life; it's going to happen, and that is okay. Get familiar with the most common kinds of errors.

Compilation error. Look for problems in the code box. (right click to inspect element?) There's a problem during execution, nan (not a number), syntax not defined, ans1=Nan. Sometimes units in ans1 throws a problem, so eliminating that in {} can be explored.

TeX validation error. Something in the TeX box is wrong; the interpreter doesn’t register what is being said. Common errors include a missing curly bracket {} or comma,

Solution job error. The problem could be anywhere; look in the error tab for a clue.  It won't tell the actual line, but may offer some tendril of what's causing problems.

Audit failure. All elements are not accounted for. Check for variable definitions, functions, misspellings and typos.

"Sorry something went wrong" error. The most frustrating and least helpful; take three deep breathes. Make a blank question in a new tab and copy or type in parts to run again. Sometimes Quest is just cranky, this is one to come back to after hours or days or get other peoples eyes on.

Getting more granular, you can click on the 'errors' tab. That may or may not offer some clues as to where the problem lies. Consider consulting this chart to see if any message there is translatable.