One forum personality, long ago, compiled a blog listing several hundred known codes, and their supposed "diagnoses" - and would later use the blog as a reference, when advising how to solve a given "bX problem". That same person showed complete lack of understanding, in a single sentence.
It's disheartening to see that the bx error code problems are still existing.The "bX" codes are not problems - they are simply symptoms of problems, identified using a canonical code structure.
In many cases, a "bX" code is simply a case of a Blogger Engineer trying to understand why one section of code is now, magically, causing another section of code to become active.
One of the most intriguing system problems, that I ever worked on, long ago, involved a hospital medical ordering system - and a doctor from Eastern Europe, who instinctively typed a "," when a "." was needed, when he was ordering medications for patients. Computer processes are very syntax sensitive - and a computer system that uses "," to separate sections of data from other sections of data, is going to have a problem with an unexpected ",", where a "." is expected.
To diagnose the problem, I had to keep the entire system (for a 1,000 bed hospital) offline for an hour, while I scanned the "console log", character by character, analysing the transaction that caused the problem. Discovering the cause of the problem required identifying this one doctor, recently arrived from Eastern Europe - and an obscure detail, knowing that people in Eastern Europe write numbers with "," and "." interchanged.
Blogger code is very complex, by necessity - from having to support people using different browsers with out of date versions - to having to support people who "confuse" syntactically essential "." and "," characters, and may write dates differently. And, Blogger code is in use on a 60 x 60 x 24 x 7 x 56 basis.
There is not one second in a 24 hour day, of a 365 (or 366) day year, that the Blogger service could ever be taken offline, worldwide, to diagnose one single "bX" related problem - let alone an entire hour, as was how the unexpected "," was diagnosed, so long ago.
That being the case, diagnosis of many Blogger problems starts with a very distributed and structured "console log", and "bX" diagnostic details. And that is all that many "bX" codes are - structured indexes into the Blogger code base, which are referenced by entries in the diagnostic logs.
There is no magic or mystery here, really. Just standard IT industry practice.