IDE 1.6.6 not starting

Hi all, downloaded the Non Admin Install version of the IDE, and unzipped it to my arduino folder as seen on the error report. The IDE started once, but will not start again, I have rebooted my system, and deleted the ‘roaming’ file. Has anyone got a resolution for this.

Many thanks

Error from arduino_debug

C:\Arduino\arduino-1.6.6-windows\arduino-1.6.6>arduino_debug
Loading configuration...
Initialising packages...
com.fasterxml.jackson.core.JsonParseException: Unexpected character ('<' (code 6
0)): expected a valid value (number, String, array, object, 'true', 'false' or '
null')
 at [Source: java.io.FileInputStream@1c229ab; line: 4, column: 2]
        at com.fasterxml.jackson.core.JsonParser._constructError(JsonParser.java
:1369)
        at com.fasterxml.jackson.core.base.ParserMinimalBase._reportError(Parser
MinimalBase.java:532)
        at com.fasterxml.jackson.core.base.ParserMinimalBase._reportUnexpectedCh
ar(ParserMinimalBase.java:453)
        at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._handleUnexpecte
dValue(UTF8StreamJsonParser.java:2278)
        at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._nextTokenNotInO
bject(UTF8StreamJsonParser.java:779)
        at com.fasterxml.jackson.core.json.UTF8StreamJsonParser.nextToken(UTF8St
reamJsonParser.java:665)
        at com.fasterxml.jackson.databind.ObjectMapper._initForReading(ObjectMap
per.java:2926)
        at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMa
pper.java:2873)
        at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.ja
va:2080)
        at cc.arduino.contributions.packages.ContributionsIndexer.parseIndex(Con
tributionsIndexer.java:171)
        at cc.arduino.contributions.packages.ContributionsIndexer.parseIndex(Con
tributionsIndexer.java:90)
        at processing.app.BaseNoGui.initPackages(BaseNoGui.java:594)
        at processing.app.Base.<init>(Base.java:292)
        at processing.app.Base.guardedMain(Base.java:219)
        at processing.app.Base.main(Base.java:135)

On doing a little further investigation, I found that the preferences.txt file is in c:\Users\XXX\AppData\Local\Arduino15 - Renamed the folder (Don’t like deleting for WIP) - and the IDE now starts fine. Not sure what the issue is! I’ll post if I find out anything.