Is There a way to prevent jForex platform from updating?
For example with editing jforex.jnlp ?

Yes, in principle you could take a "snapshot" of a version and use your own web server.

You could consider putting all supporting jar files onto your own server, and editing the jnlp launch to make that work with the specific versioned files you have......

Haven't tried it, but that might work. It might also violate intellectual copyright or other issues in the contract with Dukascopy ?? ...

HyperScalper

Do you think they remove all previous package versions from their server upon update?
Would that not be an option to save the platform starter jnlp files (with the references of old(er) packages), and use it?

On version update, the jnlp file remains the same name, same location, I believe.

So there's no redirect to a prior version without maintaining copies somewhere else.

If you understand a little about Java Web Start you could figure out what would need to be edited to serve them up from another location and server, etc.

I would love to have a "Last Known Good Platform Version" which we could fall back on, but that would take some engineering work.

HyperScalper

Friends, problem is not in platfrom itself. Problem is in java updates. Even if You will save old platfrom it will not work properly after Your java machine will update itself. jForex is constantly updating to correspond to new java features. That's why it will be correct to always use newest platfrom started from fresh jforex.jnpl file.

Just to continue hitting a dead horse...

You can stop java to update itself. So if that is the only reason why the platform sometimes receives updates that are not completely working, we can easily avoid it to happen again, can't we?