Can I upgrade from FileMaker Pro 5.5 to Filemaker Pro 11? or do I need to buy the complete application?
You will need to buy the complete new application. You will then need to convert your files to the latest format and given this large a jump in versions, you will very likely need to make some follow on adjustments to your files to get them to work correctly.
See this article for more on the conversion process: http://help.filemaker.com/app/answers/detail/a_id/750/kw/converting
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