I have encountered an issue after patch update of Ignition 8.1.26 regarding the modal setting for pop ups. Before the update, the background behind the popup is the only one being darkened and I can still interact with the buttons in the pop up. However, after the update, even the pop ups get darkened and disabled if modal setting is True. Please see image how the issue looks like.
Script for Pop-up modal:
What can we do to solve this kind of issue?
I'm also experiencing this issue intermittently 
Can you share screen shot or video clip of how you experience it? you can check a video clip of mine. 
This only happens when I open a pop up from another popup.
As part of 8.1.26, we corrected Popup behavior when dealing with multiple Popups while at least one is a modal. What you're encountering is most likely a result of those changes.
If you're dealing with multiple Popups, I'd appreciate some more information about the order-of-operations which results in the issue you're seeing.
but I just displaying single pop-up.
I attempted to replicate this behavior but was not able to. Reaching out to support would probably be a good idea. This way they can look at your system and maybe get a project export.
Okay, I'll raise it to ignition support. Thanks!
Did support resolve this issue for you?
I am having this same exact issue, but on the latest version of Ignition, currently 8.1.28.
Any updates on this? I also encountered this issue when I am opening a popup within a popup where modal properties are both set to True.
my current setup is that popup1 will close when popup2 is called. When I try to close popup2, it will not close but will become a part of the darkened/disabled area. the whole screen will be unusable and will need restart/refresh.
So I noticed this only happens when the initial popup that opens the 2nd popup has a close event aswell. Works fine if it just opens the 2nd popup without closing the initial.
Is there any update on this bug?
This function is exactly what i need for my project.
There have been multiple changes to how Popups handle closures since 8.1.26. Could you please clarify what version you're using?
Can confirm I'm experiencing identical behavior to this.
In my case, I'm launching a faceplate popup from a context menu which is a popup.
There are two events from the context menu,
The behavior you've supplied could absolutely cause issues because there is no guarantee of Action execution order. It is very likely that your "close" Action is occurring before the "open" Action.
In the event you have logic which requires an existing popup to open a second popup before then closing itself (the original popup) it is very highly recommended you use a Script Action to perform the Popup logic as this allows for sequential operations.
I did both, I should have clarified that before posting. Same behavior in a script also.
8.1.30
I'm going to have to recommend you reach out to Support for further assistance as I'm not able to replicate the behavior.
Button in "Main" View:
system.perspective.openPopup("A", "Flexy", modal=True, overlayDismiss=True, showCloseButton=True)
Button in "Flexy" View:
system.perspective.openPopup("B", "Third", showCloseIcon=True, modal=True, overlayDismiss=True)
system.perspective.closePopup("A")
When I click the Button in the Main View, a Modal-type Popup is opened (with an ID of "A"). When I click the Button within the Modal-type Popup, a second Modal-type Popup is opened and immediately after that the original Modal-type Popup ("A") is closed. My interaction with the resulting Popup is not hindered by any overlay.
Was this ever resolved? I am have a similar issue on 8.1.30 with the electronic signature framework from exchange.
Could you provide some more information regarding the setup or scenario where you're encountering this? Formatted code from any scripts and/or screenshots of Actions would be appreciated.