While troubleshooting some perfomance issues I noticed that my VM's hosting my Sage 300 environment had generic NIC's and one of them didn't have VMWare Tools installed. 

I waited until after hours and made some changes to IP's as well to those machines and rebooted them. Tested Sage 300 2018 as myself, with an admin account, and everything went OK. 

This morning however it seems that some users are having issues opening modules. One specific example is trying to open an entry on the A/R Invoice Batch List. 

Can't Create Control {GUID} followed by the Could not open UI... I have seen and read posts about those messages. Those are mostly associated to upgrades and new installs. In my case the only significant change is the ipaddress of those machines. There were a couple of DNS issues about connecting to the database but those we addressed with DNS replication and/or flushing local DNS.

This is not affecting everybody though. Just a significant portion of the users group. I cannot trigger the error on two workstation and one client install. When I try to run the application as myself on another machine I still get the errors so it does not appear to be a permissions issue. 

The related posts talk about RegAcc.exe which runs successfully but doesnt appear to change anything. I also have tried to reinstall Workstation but that does not have an affect either. 

With regards to descrepencies in PATH I ran the following PowerShell on target machines to check $env:Path -split ";" | where{-not (test-path $_)}. That would spit out any path that the computer could not access. This returns empty both on the application server and an end user computer affected by the issue.

For those that are able to work it does appear that the program is running better now.