Forums Connection Issues 10053 error, software caused connection abort

The error is coming from Symantec and it isn't unexpected that you'd get the software caused connection abort error if your antivirus blocks the connection, which is apparently happening. Why this happens on 7.19 and not older versions, I'm not sure. Various changes to mIRC may have caused that, or it may be a coincidence and Symantec updated the settings and is now blocking IRC when it wasn't before. Your best option would be to ask your work to unblock IRC. If you work somewhere that allows you to install and use software that isn't work related on your work computer, then they may do so. If you work somewhere where that is not allowed, then you shouldn't be trying in the first place.