eclips 編譯時出現 Java compiler level does not match the version of installed project facet 錯誤

今天在編譯項目時突然出現 Java compiler level does not match the version of the installed Java project facet. flower Unknown Faceted Project Problem (Java Version Mismatch) 的錯誤提示。嘗試從SVN服務器重新update 整個項目，編譯，還是報同樣的錯誤

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