Unfortunately, this is not enough information to help you. First try and make a video conference directly from a chrome web browser and if it fails, check your openfire and chrome browser logs for error messages.
It’s ok on chrome browser, an it’s ok with chrome pade plugin, only fail with spark, could you send me an installation package with sparkMeet plugin, my email is coyotek@163.com, thank you so much!
I have moved your question to a separate thread to not to clog that old blog post. Although Spark Meet jar might work with 2.8 versions of Spark, it was designed to be included in a future 2.9 version. So maybe you should try it with 2.9 nightly builds and see if it works. Although 2.9.0 is still buggy and not ready for release. https://www.igniterealtime.org/downloads/nightly_spark.jsp