Deprecated COTS java 8 app + Oracle drama, unsure where to go. Any guidance?

Pretty out of my depth here. We've got one Java 8 app left in production, provided by a third party vendor over which we have zero control or influence. The app is slated for replacement in 2025 but not until at least 2 quarters after our annual licensing window with Oracle.

Last year, Oracle slapped us with immense increases in licensing costs, and we expect them to do the same this year.

We cannot trash the app and cannot source a new vendor and cannot pressure the vendor to release alternative software. This one app is less than 1% of our total encumbrance with the vendor.

I have tried to Temurin/Azul/Coretto + OWS, it will attempt to start but will not start. I get class errors in the logs:

https://i.imgur.com/bcMv0zi.png

According to OWS forums, this is because the .jnlp file launches an APPLET, which is not supported by OWS.

[ITW-CORE][2024-08-22 14:12:41.057 EDT][DEBUG][net.sourceforge.jnlp.Launcher] Launching Applet

I am generally assuming that I am dead in the water, and that's OK. I just don't know where else to go or whom else to ask for alternatives. I did find cheerpj and some decent feedback but again, as we are not HOSTING this applet I'm not sure if it can help us. (Or if it's any cheaper, but I can begin evaluation.)