Solution:
An HCF/halt-and-catch-fire instruction.
Process below.
The message is
$\cot{\theta}$
Reasoning:
The final "4" is a dead giveaway that it's a Unicode-formatted text stream, since 0x4
is the end of file character. The preceding set consists of 99 -> 0x63
-> "c", 111 -> 0x6F
-> "o", 116 -> 0x74
-> "t", 120579 -> 0x1D703
-> mathematical symbol italicized lowercase $\theta$.
Therefore what you lack is
Encoding. The examples provided all refer to unprocessed data: uncompiled code, a date without a calendar standard to make it mean something, coordinates without a GIS database, a string without a dictionary, the raw input $\cot{\theta}$ without Unicode encoding, and the value $\tan{\theta}$ without multiplication by $\cot{\theta}$ to cancel it out.
Thus,
Given the references to fire, the world just ceasing to exist, and the cessation of output,
You have seen
A halt-and-catch-fire instruction, a term for an instruction that when executed completely and unrecoverably stops the CPU from doing anything useful,
And to see your dream you need
To reboot the system.
Edit: To make this a complete solution I determined a reading of the poem that works with this context.
"When the world is dark":
"Dark" in the sense of "provides no signal," since nothing can execute.
"Nothing seems so stark":
One possible meaning of "stark" is "rigid," like a system that is completely unchanging due to having run Halt and Catch Fire.
"End is all that I don't see":
The program never halted, it's just hanging indefinitely.
"All I can do is flee":
On the original halt-and-catch-fire instruction, the unrecoverable cessation of function was due to the instruction pointer constantly incrementing without being able to process the code at that memory address. Thus, you (the instruction pointer) are constantly fleeing from the code you're supposed to be running.
wordplay
tag should be present. It's vague, this whole site is vague. What is wordplay even defined as? This puzzle contains vague no "wordplay" in the classical sense but there is wordplay and if I explain how, I'll spoil it. Even though making it into $\tan$ wouldn't be detrimental, it won't matter because it's not a maths problem, it's just that you need to have some math capabilities. I've chosen the specific trig so that it's more thrilling. $\endgroup$