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The automated one-click solution introduced in connector version 6.3.0.0 follows these steps. Thus, if you are running connector version 6.2.1.0 or older, you can follow the proceedure manually.
Step #1 - Enable Flat Catalog
Check if Flat Catalog is enabled under System → Configuration → Catalog → Frontend:
Step #2 - Reindex Category Index
Reindex Category Flat Index in System → Index management:
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#3 - Flush Cache Storage
Click Flush Cache Storage button under System → Cache Management:
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