Arduino 1.6.4が起動しない原因はどこだ?

コマンドプロンプトを開いて、そこから arduino_debug.exe を起動すれば、こんなログが取れる

Microsoft Windows [Version 6.3.9600]
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C:\Dropbox\arduino\arduino-1.6.4>C:\Dropbox\arduino\arduino-1.6.4\arduino_debug.
exe
Loading configuration…
Initializing packages…
Board variant:328IntRC:328IntRC doesn’t define a ‘build.board’ preference. Auto-
set to: 328INTRC_328INTRC
Warning: platform.txt from core ‘Specialty clone Boards’ contains deprecated com
piler.path={runtime.ide.path}/hardware/tools/avr/bin/, automatically converted t
o compiler.path={runtime.tools.avr-gcc.path}/bin/. Consider upgrading this core.

Warning: platform.txt from core ‘Specialty clone Boards’ contains deprecated too
ls.avrdude.cmd.path={runtime.ide.path}/hardware/tools/avr/bin/avrdude, automatic
ally converted to tools.avrdude.cmd.path={path}/bin/avrdude. Consider upgrading
this core.
Warning: platform.txt from core ‘Specialty clone Boards’ contains deprecated too
ls.avrdude.config.path={runtime.ide.path}/hardware/tools/avr/etc/avrdude.conf, a
utomatically converted to tools.avrdude.config.path={path}/etc/avrdude.conf. Con
sider upgrading this core.
Warning: platform.txt from core ‘Specialty clone Boards’ misses property tools.a
vrdude.path, automatically set to {runtime.tools.avrdude.path}. Consider upgradi
ng this core.
processing.app.debug.TargetPlatformException: Could not find boards.txt in C:\Us
ers\B\AppData\Roaming\Arduino15\packages\arduino\hardware\avr\1.6.2. Is it pre-1
.5?
at processing.app.debug.LegacyTargetPlatform.<init>(LegacyTargetPlatform
.java:67)
at cc.arduino.contributions.packages.ContributedTargetPlatform.<init>(Co
ntributedTargetPlatform.java:43)
at cc.arduino.contributions.packages.ContributionsIndexer.createTargetPa
ckages(ContributionsIndexer.java:307)
at processing.app.BaseNoGui.loadContributedHardware(BaseNoGui.java:777)
at processing.app.BaseNoGui.initPackages(BaseNoGui.java:615)
at processing.app.Base.<init>(Base.java:271)
at processing.app.Base.guardedMain(Base.java:215)
at processing.app.Base.main(Base.java:128)

C:\Dropbox\arduino\arduino-1.6.4>

そんなわけで board.txt がないと言っているようだ
そして B\AppData\Roaming\Arduino15\packages\arduino\hardware\avr\1.6.2 は空っぽだ。もう面倒なので自動生成されたと思われる Roaming\Adrudino15 を消してみたらIDEが起動した

Roaming\Arduino15は再び生成されていたけど、シンプルだった