Tried to open JOSM, it didn't respond - my laptop is getting elderly, so I clicked again and left it to do its thing. When I came back there were 3 JOSM windows. I deleted 2 of them and found the error msg. Hope this helps.

[shiller27@…]

What steps will reproduce the problem?

What is the expected result?

What happens instead?

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: 2017-04-02 01:45:00 +0200 (Sun, 02 Apr 2017)
Build-Date:2017-04-02 01:34:50
Revision:11826
Relative:URL: ^/trunk

Identification: JOSM/1.5 (11826 en_GB) Windows 7 64-Bit
Memory Usage: 32 MB / 247 MB (17 MB allocated, but free)
Java version: 1.8.0_111-b14, Oracle Corporation, Java HotSpot(TM) Client VM
Screen: \Display0 1366x768
Maximum Screen Size: 1366x768
VM arguments: [-Djava.security.manager, -Djava.security.policy=file:<java.home>\lib\security\javaws.policy, -DtrustProxy=true, -Djnlpx.home=<java.home>\bin, -Djnlpx.origFilenameArg=%UserProfile%\AppData\LocalLow\Sun\Java\Deployment\cache\6.0\56\1ee8cfb8-42b24e09, -Djnlpx.remove=false, -Djava.util.Arrays.useLegacyMergeSort=true, -Djnlpx.splashport=52255, -Djnlp.application.href=https://josm.openstreetmap.de/download/josm.jnlp, -Djnlpx.jvm=<java.home>\bin\javaw.exe]

Plugins:
+ buildings_tools
+ turnrestrictions

Last errors/warnings:
- E: Handled by bug report queue: java.lang.SecurityException: Can not verify security pack jar due to certificate exception. Cause: java.util.zip.ZipException: error reading zip file


=== REPORTED CRASH DATA ===
BugReportExceptionHandler#handleException:
No data collected.

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: Thread-22 (58)
java.lang.SecurityException: Can not verify security pack jar due to certificate exception
	at com.sun.deploy.util.SecurityBaseline.verifyJar(Unknown Source)
	at com.sun.deploy.util.SecurityBaseline.access$200(Unknown Source)
	at com.sun.deploy.util.SecurityBaseline$1.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)
Caused by: java.util.zip.ZipException: error reading zip file
	at java.util.zip.ZipFile.read(Native Method)
	at java.util.zip.ZipFile.access$1400(Unknown Source)
	at java.util.zip.ZipFile$ZipFileInputStream.read(Unknown Source)
	at java.util.zip.ZipFile$ZipFileInflaterInputStream.fill(Unknown Source)
	at java.util.zip.InflaterInputStream.read(Unknown Source)
	at java.io.FilterInputStream.read(Unknown Source)
	... 4 more