You have a network ban (K-Lined / G-Lined / Z-Lined) against your IP address for the financialchat network.

You need to follow the directions of the ban message and email one of the addresses with the "Closing link: ..." line.

Reference: https://forums.mirc.com/ubbthreads.php/topics/22819

Quote
I installed the newest version, 7.83 on my WinXP computer, but the problem persists.

Based on your message the IRC client you use does not matter. Its your IP address of where you are connecting from is the issue.

Quote
I tried la different network (LiberaChat) and didn't have the problem.

Each IRC network is different.

Quote
On my second computer the problem is also present with #iNewsroom on financialchat.com

IP address ban.