Sorry, I thought I had responded this morning... I'm sorry for the frustration.

From the other post it sounds like the login dialog comes up, but you can not enter any information in it. Is that correct? You see something like below, but it's not letting you type anything in the fields?

If so, let's try a few things.  

1) Please add the line in bold below to C:\ProWin20\32bit\protax20.exe.config, exactly as shown below above the </appSettings> line.  (If you are using Basic it will be C:\BasWin20\32bit\protax20.exe.config)

<appSettings>
<add key="Intuit.TPS.Information" value="TpsBridge-5.13.1" />
<add key="log4net.Config" value="log4net.config" />
<add key="log4net.Config.Watch" value="True" />
<add key="Intuit.Spc.Authorization.EmbeddedWebBrowserImplementation" value="Standard"/>

</appSettings>

Then restart ProSeries. This will switch the technology used to show the login screen. If it works, we'll know it's a problem with the default technology we are using. I will have some followup questions if so, to help figure out why it's happening.

2) If you are comfortable searching for a hidden file, please send C:\Users\ocardoso\AppData\Local\Intuit\Common\Authorization\v3\Logs\IntuitAuthLog.txt to proseries_engineering@intuit.com.  That might help us troubleshoot.