Description:
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Hello.i download new help chm files(Date: 5 Jun 2015), and i can not use search,no matter what i input,It always tell me can not find.i have download some version(manual_en, enhanced_en, manual_zh, enhanced_zh),But it is the same problem. 

i search this problem, and i find the same in #66432.

Test script:
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no script

Expected result:
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let me search please!

Actual result:
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no matter what i input,It always tell me can not find