; Some legit uses:
>> try/except [1 / 0] func [e] [print mold e]
make error! [
    code: 400
    type: 'Math
    id: 'zero-divide
    arg1: none
    arg2: none
    arg3: none
    near: [/ 0]
    where: [/ try]
]
>> try/except [1 / 0] func [e] [type? e]
== error!
; Note that the lack of typespec for the argument may not be technically correct, but looks better.

; Iffy but acceptable examples (don't crash)
>> try/except [1 / 0] func [e [integer!]] [type? e]
== error!
>> try/except [1 / 0] :load
** Script error: file-type? does not allow error! for its file argument
** Where: case applier try
** Near: case [
    block? source [
        return map-each x source ...
; Note that LOAD errors out on the inside, but doesn't crash R3

; Some correct and semi-useful natives that accept error args
>> try/except [1 / 0] :mold
== {make error! [
    code: 400
    type: 'Math
    id: 'zero-divide
    arg1: none
    arg2: none
    arg3: none
    near: [/ 0]
    where: [/ try]
]}
>> try/except [1 / 0] :form
== {** Math error: attempt to divide by zero
** Where: / try
** Near: / 0
}
>> try/except [1 / 0] :print
** Math error: attempt to divide by zero
** Where: / try
** Near: / 0
; If natives were excluded then these wouldn't work, but that might not be too bad.

; And here is the problem: A native that doesn't accept errors.
>> try/except [1 / 0] :add
; R3 crashes without even a system exception, the process just dies.