Combine (C) tools function is abnormal

[Akrimullah]

What steps will reproduce the problem?

1. Wanna combine two different road segment (any classification)
2. I press shortcut C or go to tools menu and Combine.
3. The result frequently shows nothing happens. Two roads couldn't be combined.

What is the expected result?

What happens instead?

Combine tools didn't work properly. Sometimes it works, but mostly it didn't work.

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

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2018-11-28 01:09:01 +0100 (Wed, 28 Nov 2018)
Build-Date:2018-11-28 00:26:41
Revision:14460
Relative:URL: ^/trunk

Identification: JOSM/1.5 (14460 en) Windows 10 64-Bit
OS Build number: Windows 10 Pro 1511 (10586)
Memory Usage: 845 MB / 989 MB (168 MB allocated, but free)
Java version: 1.8.0_144-b01, Oracle Corporation, Java HotSpot(TM) Client VM
Screen: \Display0 1366x768
Maximum Screen Size: 1366x768
Dataset consistency test: No problems found

Plugins:
+ DirectUpload (34502)
+ apache-commons (34506)
+ buildings_tools (34724)
+ ejml (34389)
+ geojson (87)
+ geotools (34513)
+ imagery_offset_db (34641)
+ jaxb (34506)
+ jts (34524)
+ opendata (34698)
+ todo (30306)
+ turnrestrictions (34643)
+ utilsplugin2 (34506)

Tagging presets:
+ F:\PROJECTS\HOT\WFP YOGYA\Pelatihan OSM Universitas Negeri Yogyakarta\02 Software\Preset\OSM_Indonesia_Presets_Ver.3.2.xml
+ F:\PROJECTS\HOT\FACEBOOK\FBS\FB_presets.xml

Map paint styles:
- F:\PROJECTS\HOT\FACEBOOK\FBS\FB_style.mapcss
+ F:\PROJECTS\HOT\FACEBOOK\FB\FB_style.mapcss

Validator rules:
+ F:\PROJECTS\HOT\FACEBOOK\FBS\FB_rules_HOT.validator.mapcss

Last errors/warnings:
- W: Unable to convert property casing-color to type class java.awt.Color: found #0023b21 of type class java.lang.String!
- W: Unable to convert property casing-color to type class java.awt.Color: found #0023b21 of type class java.lang.String!
- W: Unable to convert property casing-color to type class java.awt.Color: found #0023b21 of type class java.lang.String!
- W: Unable to convert property casing-color to type class java.awt.Color: found #0023b21 of type class java.lang.String!
- W: Unable to convert property casing-color to type class java.awt.Color: found #0023b21 of type class java.lang.String!
- W: Unable to convert property casing-color to type class java.awt.Color: found #0023b21 of type class java.lang.String!
- W: Unable to convert property casing-color to type class java.awt.Color: found #0023b21 of type class java.lang.String!
- W: Unable to convert property casing-color to type class java.awt.Color: found #0023b21 of type class java.lang.String!
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out