Hi Jeongkyu
We have validated your reported queries.
Query 1: “ Is there any way to find out which version of ej2.min.js is used on our website?
(The site that we run is "15.2.0.40" when you hit Syncfusion.version in the Chrome Developer Tools. https://cdn.syncfusion.com/ej2/dist/ej2.min.js given as an example attribute is Syncfusion. I am wondering if this is the version.)”
If you have generated scripts(ej2.min.js) through CRG site, there is no details about version identification. We are very sorry that we couldn't suggest solution when the version of script which you have used.
Query 2: “If you use the latest ej2.min.js (I guess it's version 18.2.46) file, please inquire if there is any effect on existing components.”
We will assist you the solution if you upgraded to latest version. Could you please upgrade to latest release?
Query 3: “We rely on buttons and graphs as well as a lot of them, and I'm afraid that if the major version changes, we're going to encounter custom CSS or javascript issues.”
Can you share the components which you have used other than buttons and charts with us. Also, backup your project and upgrade it with latest. If you faced any issue and want to revert back, you can restore backup source.
Please get back to you if you face any difficulties,
Regards,
Indrajith