Raster layer 'New offset' does not terminate on OK, UI blocked on layer offset setup

[dido]

What steps will reproduce the problem?

1. Download data
2. Open Bing raster layer
3. Offset Bing raster layer and hit OK

What is the expected result?

Exit Layer offset mode, vector data editable

What happens instead?

Still in Layer offset mode, vector data not editable, left mouse button drag still offsets Bing raster layer. Another click on layer's 'New offset' does not provide dialog (dialog still opened but invisible ?)

Please provide any additional information below. Attach a screenshot if possible.

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2016-09-06 00:16:07 +0200 (Tue, 06 Sep 2016)
Build-Date:2016-09-05 22:21:00
Revision:10966
Relative:URL: ^/trunk

Identification: JOSM/1.5 (10966 en) Windows 7 64-Bit
Memory Usage: 300 MB / 989 MB (62 MB allocated, but free)
Java version: 1.8.0_91-b15, Oracle Corporation, Java HotSpot(TM) Client VM
Screen: \Display0 1680x1050
Maximum Screen Size: 1680x1050
Dataset consistency test: No problems found

Plugins:
+ CommandLine (32796)
+ SeaMapEditor (32767)
+ continuosDownload (53)

Tagging presets:
+ -

Map paint styles:
+ -

Last errors/warnings:
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet
- W: java.io.IOException: Attribution is not loaded yet

OSM API: http://---/api

[Klumbumbus]

Closed as duplicate of #13561.