Hi.
Here in my office, our computers have been restored and up-to-date, and now anyone who’s trying to run Dynamo Player has the same issue: the window appears for a sec and then disspears, even from Window’s Taks Manager. The button remains ‘greyed’, like it is running already, but we can not find it anywhere.
I read about deleting the folder called ‘dynamoplayerinstance 1’, tryed, but it appears again and again.
Anyone with a solution? I’d be really thankful.
*We are using latest version (1.3.4.6666).
Does Dynamo work? Open Dynamo first and close it. Then try opening DynamoPlayer
Yes, Dynamo works perfectly. After closing it, Dynamo Player´s button remains grey.
May be that the window is offscreen after someone with a different monitor setup configured things.
Hold alt and tap the tab key to see if it’s visible in the list of open programs.
If so tap tab until you cycle through to it.
Then hold Alt and tap the space bar, then tap the M key, release alt and tap any arrow on the keyboard.
Move the mouse.
The Dynamo Player window should show up on screen.
If it doesn’t show in the list of open programs, check task manager for Dynamo Player to see if it’s forced to closed by part of your infosec settings.
Have done all of these and still doesn’t work 
No window seems to be active, and can’t find it in any task manager’s tab.
Can you do a screencast showing the details tab of the task manager and the ‘brief appearance’ for review? Also what happens when you launch Dynamo? The journal from your Revit session would also help.
Same situation hehe, but with Civil 3D 
We’d need more info to help. This might be a good place to start if you can’t find player to move it onto screen via ALT + TAB keys.
I’m going to screencast this happening, but it is like this: as I open Dynamo, I try to Alt+Space to access the “Move” window command through keybord and find it somewhere, but it doesn’t work. Neither the Alt+Tab to find Dynamo Player window.
And the Dynamo with its UI works perfectly.