We have three systems all 500 linked with point to point.
MGI works sometimes but other times it states out of order.
It is very spotty when and for how long it happens.
You can call one location but they can't call you.
In time it fixes its self.
Any suggestions?

Possible IP address conflict with the MGI channels on the network. - One of many things that might possibly cause similar behavior.

There was a fix for this in Version 2.75. Check your software versions in all 3 systems. I had a similar problem with an 8 location customer and this fixed it.