This morning, of course, the problem so far has not arisen and the error message has yet to appear when connecting the 2 computers.Perhaps it just needed a restart to settle things down.

I will enclose the logs anyway:
The "failplan-g.log" is after various attempts to get it to work, and the "OKplan-g.log" is just from this mornings successful attempts.

Perhaps you might find an anomaly somewhere.

Same wideFS on both, and disabled traffic but no joy so far.

I will keep experimenting.

Thanks, Tim, for speedy and helpful reply.

Will check out your suggestions as soon as I can.

I'll let you know the result in case it may help someone else.

I have been using this great flight aid on one computer, then I installed Plan-G on a small Toshiba and linked it to my FSX computer using wide FS, without trouble. I am using the latest version of Plan-g.

I have now installed Plan-g on an HP laptop and if I attempt to link it to FSX as I did before with the Toshiba, the small aircraft icon appears on the map but almost immediately the windows error message pops up saying the program has stopped working.

I also have Flight Keeper and Flight Commander on this HP computer and they link to the FSX computer using wideFS without trouble.

It is obviously a problem with the set-up on the HP computer, but I have tied reinstalling Plan-g and it has made no difference.
Sometimes if I use the "clear all settings" program in the main Plan-g directory and start  Plan-g as an administrator although I have already set this as the normal start situation, then it will run OK without stopping, but this can not be relied upon.

Has anyone else had this weird occurence and any clues to fix it?