JHelioviewer 2.15.4.9298 not working after installation on Windows 10

[Sophie M]

I just installed JHelioviewer on my laptop and it is not working. I used the 2.15.4.9298 installation file for jhv. I am on Windows 10.

When I start the application I get the message box:

An error occurred while opening the remote file:
java.net.ProtocalException: Invalid HTTP response: HTTP/1.1 500 Internal Server Error

I thought it was the problem described in the troubleshooting section of the jhv manual so I did the following:
I checked my system type; it is x64-based PC
I check the version of java, I got:

java version "1.8.0_191"
Java(TM) SE Runtime Environment (build 1.8.0_191-b12)
Java HotSpot(TM) Client VM (build 25.191-b12, mixed mode, sharing)

(and so, I do not see if this is a 32 or a 64 version of java)

Even so, I still followed the instructions to install manually java, but the problem persist.
My poor knowledge in computer science makes me unable to know what is likely to be the problem or what should be the next step, so I need your help. I am sorry if this is a common problem, I did a (really) quick web search but did not find an answer, so I'm posting this.

Thanks in advance for your help,
Regards