I've installed the prerequisite r-base and the rstudio's deb package without a problem. However, when I open a menu option in RStudio which then opens a Gnome dialog, the dialog popup could only be closed but it would not accept any mouse clicks.
For example, trying to set the 'Default working directory (when not in project)' in 'Tools -> Global Options -> General'. The 'Browse' button opens a Gnome dialog listing the content of the home directory. The dialog window would not respond to any mouse clicks, except on 'Cancel', and thus no selection can be made.
There is an error printed in the linux terminal:
Gtk-Message: GktDialog mapped without a transient parent. This is discouraged.
It seems like this is an issue unrelated to R Studio. For a similar issue on Ubuntu but another software application, the suggestion was to ignore the message.
I'm using R version 3.6.1 with RStudio Version 1.2.5001 on Kubuntu 19.10 without any problems.
Thanks for the response drevanzyl.
Sure, I can ignore the message but, I can not ignore the problem. The GtkDialogs open by the RStudio menu options would not scroll nor highlight nor respond to double clicks. This means I can select, 'blindly' as the selection in the popups is not highlighted, the list of files/dirs does not scroll down nor subdirectories are expended.
I'm also in the dark here. I haven't seen similar issues with RStudio and Ubuntu. It seems to me like the issue is with the version of Gtk or zenity you might be using.
Did you recently install Ubuntu and did you use the standard installation with default settings and applications? Is it installed on a server or your desktop/laptop?
Try to install the latest version of Gtk and zenity.
Try a different desktop environment like Kubuntu (KDE), Ubuntu Mate, Xubuntu.
If possible, try the latest version of Ubuntu. I've used the latest R Studio on Ubuntu 19.04 but not on 18.04. I'm currently using it on Kubuntu 19.10 without any problems.
Who would have thought, a simple re-boot would fix it.
My machine is a development desktop. I have regular Ubuntu 18.04.3 updates running periodically but I don't reboot each time I'm prompted because often I have too many terminal layouts to reset.
The machine hadn't been rebooted for a long time. It is possible some Gtk update/config or some lib wasn't in a proper state.
After the reboot, the RStudio-invoked GtkDialogs work fine (the warning is still there, but as you said, it is just a warning).