1 Client out of around 100 cannot connect to Openfire 4.8.3 server

Our environment is:
Openfire 4.8.3
Spark 3.0.2

As of today, one Client cannot connect. I enabled debugging in Spark, and it is sending packets to the server but not getting anything back. I deleted the users account on the server and had them create another one. This had no affect. I remote connected to the users computer, uninstalled Spark, making sure to delete the AppData/Roaming/Spark folder and making sure that the Program Files folder was gone completely as well.
I also uninstalled OpenJDK and reinstalled that.
Reinstalled Spark. Same exact result. The user sent me a screenshot of the error message with the detail expanded. I’ll attach it to this message.

After the reinstall, the connection isn’t even getting to the point where it is asking the user to accept the security certificate. There is absolutely no response from the server in the RAW Data Received tab of the debugger.

If anyone has any ideas what is going on, any help would be great. No one else is having any issues at all.