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The discrepancy in validation messages between ColdFusion 4.51 and 2023 may stem from platform updates. No CF Admin setting likely replicates the 4.51 behavior. Adapt by implementing JavaScript validation to mimic previous functionality. Given the VARCHAR field, ensure validation handles non-numeric inputs. While an additional task, client-side validation enhances user experience with instant feedback. Monitor ColdFusion documentation and forums for insights into changes and best practices. Remember, thorough testing is crucial to ensure validation accuracy and user satisfaction.

For the discrepancy in validation messages between ColdFusion 4.51 and 2023, first check ColdFusion Administrator settings for relevant configurations. If none are found, adapt to changes by implementing client-side JavaScript validation for simplicity and customized error messages. Given the VARCHAR field, ensure the validation logic handles non-numeric inputs. Although an additional task, client-side validation enhances user experience with instant feedback. Stay informed by monitoring official ColdFusion documentation and community forums for insights into changes and best practices in the latest versions.

I think that the presence of the semi-colon(;) is the cause of the problem.

VALUE="MAX=999999;MIN=10000"

As @AlexCraig has already shown, replacing the semi-colon with a comma(,) solves the problem. The following (a space in place of the semi-colon) would also work

VALUE="MIN=10000 MAX=999999"

Guess what?

Searching further, I found that the two currently documented delimiters to use are comma and space.  See the documentation on cfinput's range attribute and the page "Validating form data using hidden fields".

I am currently in the process of migrating from ColdFusion 4.51 to ColdFusion 2023, as mentioned in the subject line and the first line of my initial inquiry. However, it seems there might be a misunderstanding, as your response requests the version I am planning to migrate from.

To clarify, I am migrating from ColdFusion 4.51 to ColdFusion 2023. If you require any additional information or if there's a specific process I should follow, please advise.

Alex, when I first wrote, I focused on how CF form validation is done via cfinput (and I showed how even the cf docs for 4.51 showed that), and how that approach requires a comma-separated min/max value for its RANGE feature. I wondered if instead you had some other js library using the attributes of the input tag as you showed it. 

Then I noticed it was both a hidden input,with a NAME field ending with _range as a suffix, AND that validation in the VALUE attribute. That reminded me there was another, older form of field validation cf did that was entirely server side (thus your message). I've not seen it in years, but it was coming back to me. 🙂 

And sure enough, I found another cf 4.51 docs page on that, showing the min/max specified as you do. Note that it's not in the cfml reference, because it's not a cf tag, but a way cf handled form fields based on the suffix of their names, as with _range in your example. 

Anyway, the current docs for that page don't show that range being supported at all, which suggests Adobe deprecated it...but clearly it's still "working" for you. 

Can you try just changing the value to "10000,999999" to see if that works? I'm on a phone so can't easily test that myself.