We have found an issue with the installer of PVRCarbon (confirmed versions R1, R2). I haven’t found any mentioning of it on the forum. Basically, the installer (requires sudo) seems to be breaking the mime types and preventing the GTK from accessing themes, icons etc. As result, no icons or any other theme-related items display anymore and all UI apps crash. Reinstalling GTK and triggering shared-mime-types seems to bring everything back to normal. This behaviour has been confirmed on several PCs and is 100% connected with the PVRCarbon installer.
To Imagination: please, fix it. If the installer needs root access, test it thoroughly. With great power… and you know the rest.