PV Plus and FactoryTalk Problem

Hi,
I have a stange problem concerning FactoryTalk and PanelView Plus.
We had a PV1400e communicating with 4 SLCs before, and We wanted to upgrate it to PV plus. But when I configured the communication the same as the old PV 1400e, and I am sure the configuration is correct, the PV Plus just cannot communicate with 2 of the 4 SLCs.
So I had to change the system back to the old PV 1400e. But today I compiled the application in another PC and downloaded it to the PV Plus, it worked well.
I am so confused. I guess that maybe there are some problem with my previous PC, but when I used it in other occasions, it worked very well. Or maybe the FactoryTalk installed in my previous PC was not match my PV Plus. Or maybe the PC itself was not match the PV Plus.
I have asked the question to some experienced engineers, they all said that they also met this problem before, and they used to reinstall the software then reinstall the OS, then change a PC. They don't why, but this solution just works.
But I want to know why. Dose anyone know that. Please help me.
Thanks very much.

Program written in FTV V4.0 only work in PV+ with V4.0 runtime.

Thanks, bttony.
But firstly, my application could run previously with 2 of the 4 SLCs. Secondly, when I changed PC to compile the program, it could work well.
And the two PCs had the same version FTV.

Get used to it. FTView is the definition of insanity. Do the same thing over and over again and expect different results.

OkiePC said:

Get used to it. FTView is the definition of insanity. Do the same thing over and over again and expect different results.

Click to expand...

Nicely put. I'm adding that to my Signature...

This morning, (while still trying to resolve my AutoCad licensing issue that the FTView install broke), I started FTView 5.10, and got past the select edition screen, then the window vanished leaving only the taskbar indicator. I gave it a few minutes (FTView needs a lot of time to "think"), and finally had to force it closed with task manager.

I did some other work, then started it again, and this time it allowed me to choose an application. Then it gave an error, something about not having the rights to "edit or list children", I puzzled over that for a bit, then clicked OK. It continued to open, but then barked at me again, saying it could not load the HMI server. When it finally got done "thinking", my directory tree was missing half the stuff it needed.

Before break, I shutdown all the apps, and restarted the machine (that's getting to be a regular habit...reboot three or four times a day)...

Now it's running normally...

Gotta love it.

I see ROK stock is up 8.5% today.

It's really the same success story as Bill Gates' company. Don't give them what they need, give them what they want...conflict...Modern humans don't get enough conflict in their lives without things like windoze and factorybalk to fill in that void...

OkiePC, good complaint.
So, you believe my question is the FTView software problem. Maybe the software works differently in different PC or in different OS or at different time.
Maybe I should expect the later version FTView be better or pray god bless me.