>>we have implemented all the solutions available from the web as well.
What would those be?
The debugger reaches out from the database TO your client. Make sure network security isn't blocking that comm coming out of the db server.
If it were an ACL issue, you'd get an ACL error. It's more likely the firewall is getting in the way on outbound traffic from the db server.
I am reiterating what other have said but ...
How the sql developer debugger works is that opens up a listening port, in your case 52089, on your pc (ip: 10.0.8.236).
what the error message is saying is that the database can not connect to this port.
A couple of things ... (some have already said this)
Check any firewall settings that you may have on your local pc (re: windows firewall).
It may be worth setting your sqldeveloper to a limited range or fixed listening port to make it easier. (this is in the sqldeveloper config) - this is just for convenience rather than needs to be done.
else it is up to you and your IT team to allow access from the DB to toy PC.