Olli73

As local variable it is not initialized, as global it is.

Which database and components? What are the settings for lockmode, isolation level and so on? In debugger there are shown exceptions by default always. The user (no debugging) will not see it. I think we need more details.

I have no experience with such a setup, but I would try to use "TDSProviderConnection.AfterDisconnect" event to start a timer which tries every second to call a "TDSProviderConnection.Open" until "TDSProviderConnection.connected" is true again. As long as the timer runs you block all actions which load or save data from/to the server.

It is better to use a HTTP-/Rest-Server ... You could easily fill a client dataset on client in this way: On Server you make a Query and then via a provider you load it into a clientdataset. Out of that you can use a command to make XML or JSON of it. That XML/JSON you send (as a result of a get query from client) to the client and with a command you can generate a filled ClientDataSet on Client and work then with that. The other way, to update the database on server, could be a little bit more complex.

var ItemClickEvent: TCustomListBox.TItemClickEvent;

I would try another way: Make a dervied class from TWebRowser and make MouseClick (or MouseDown / MouseUp) function(s) public there. Now call this function(s) with your mouse cursor coordinates.