opening a random layer at the first time in the session an error appears

[anonymous]

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: 2016-06-04 17:28:58 +0200 (Sat, 04 Jun 2016)
Build-Date:2016-06-04 15:31:27
Revision:10327
Relative:URL: ^/trunk

Identification: JOSM/1.5 (10327 en) Windows 10 64-Bit
Memory Usage: 798 MB / 1778 MB (357 MB allocated, but free)
Java version: 1.8.0_91-b14, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Dataset consistency test: No problems found

Plugins:
- DirectDownload (32158)
- DirectUpload (32158)
- HouseNumberTaggingTool (31926)
- ImportImagePlugin (32158)
- Mapillary (32158)
- OpeningHoursEditor (32158)
- PicLayer (32158)
- RoadSigns (32177)
- apache-commons (32158)
- apache-http (32158)
- buildings_tools (32158)
- download_along (32158)
- editgpx (32223)
- ejml (32158)
- ext_tools (32158)
- geotools (31895)
- jts (31906)
- log4j (32158)
- measurement (32158)
- ods-bag (0.6.7)
- opendata (32158)
- opendataservices (0.6.7)
- pbf (32158)
- photo_geotagging (32158)
- poly (32158)
- reverter (32158)
- terracer (32158)
- turnlanes (32158)
- turnrestrictions (32158)
- utilsplugin2 (32158)
- wikipedia (32182)

Map paint styles:
- Y:\== Routes\JOSM\== BAG\BAG Import Plugin Open Street Map JOSM\BAG\BAG\Style Sheet Peewee\Style Sheet Fin (Ilpo) over NL borden\nlsigns\nlsigns-all.mapcss
- Y:\== Routes\JOSM\== BAG\BAG Import Plugin Open Street Map JOSM\BAG\BAG\bag-plugin-0.6.6\Bag-plugin-0.6.6\Ods-bag-style-0.6.6.mapcss
- https://dl.dropbox.com/u/8010189/Forum%20attachments/Hide_nodes.mapcss
- https://github.com/gmgeo/osmic-josm-style/archive/master.zip
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_Streets&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_buildings&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/LessObtrusiveNodes&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Potlach2_access&zip=1
- https://raw.githubusercontent.com/yopaseopor/traffic_signs_style_JOSM/master/Styles_Traffic_signs.zip

Last errors/warnings:
- W: Ext_Tools warning: can not load file <josm.pref>\plugins\ext_tools\tools.cfg
- W: Ext_Tools warning: can not load file <josm.pref>\plugins\ext_tools\repo.cfg
- W: Cannot start IPv4 remotecontrol https server on port 8112: Keystore was tampered with, or password was incorrect
- W: Cannot start IPv6 remotecontrol https server on port 8112: Keystore was tampered with, or password was incorrect
- E: java.lang.IllegalArgumentException: Negative position

java.lang.IllegalArgumentException: Negative position
	at sun.nio.ch.FileChannelImpl.write(Unknown Source)
	at org.apache.commons.jcs.auxiliary.disk.block.BlockDisk.write(BlockDisk.java:216)
	at org.apache.commons.jcs.auxiliary.disk.block.BlockDiskCache.processUpdate(BlockDiskCache.java:399)
	at org.apache.commons.jcs.auxiliary.AbstractAuxiliaryCacheEventLogging.updateWithEventLogging(AbstractAuxiliaryCacheEventLogging.java:65)
	at org.apache.commons.jcs.auxiliary.disk.AbstractDiskCache.doUpdate(AbstractDiskCache.java:815)
	at org.apache.commons.jcs.auxiliary.disk.AbstractDiskCache$MyCacheListener.handlePut(AbstractDiskCache.java:673)
	at org.apache.commons.jcs.engine.AbstractCacheEventQueue$PutEvent.doRun(AbstractCacheEventQueue.java:350)
	at org.apache.commons.jcs.engine.AbstractCacheEventQueue$AbstractCacheEvent.run(AbstractCacheEventQueue.java:269)
	at org.apache.commons.jcs.engine.CacheEventQueue$QProcessor.run(CacheEventQueue.java:304)

[wiktorn]

Closed as duplicate of #12979.
This is already fixed in current JOSM. For stable version, you'll need to manually remove the files in directory:

%LOCALAPPDATA%\Josm\cache\tiles

One of the file grew to 2GB and stable JOSM doesn't handle well this situation.