ImageJ hangs after trying to open file from menu

[Pavlo Shchelokovskyy]

System: Ubuntu 15.10 x64,
Package versions:
- ImageJ 1.49i+dfsg-1
- openjdk-7-jre 7u91-2.6.3-0ubuntu0.15.10.1

Reproducer:

1. Open an image with ImageJ from Nautilus via file context menu (Open With -> ImageJ)
- Image opens in ImageJ
2. Now try to open another image from ImageJ's own menu (File -> Open...)

Expected: second image opens in the same instance of ImageJ

Result: ImageJ hangs after pressing "Open..." menu entry, without showing the file dialogue. Window is unresponsive. Only terminating ImageJ process and its child Java processes helps (via System Monitor or "kill" command).

Might be related: after opening an image with "imagej" from command line the following hint appears:
Open other images in this ImageJ panel as follows:
  imagej -p 7 <image1> [<image2> ... <imageN>]

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.