1、原因：
ORA-12737: Instant Client Light: unsupported server character set CHS16GBK
Google，解释如下：
ORA-12737:
Instant Client Light: unsupported server character set string
Cause: The character set specified is not allowed for this operation or is invalid. Instant Client Light has only minimal character sets.
Action: Do not use Instant Client Light for this character set
2、解决办法，我们打开“tools”-->"options-〉选项-〉其他-〉oci"菜单，见到如下界面，依据OCI library(oci.dll) 路径，导航到 navicat oci 目录下，备份里面的文件（通过在该目录新建bak文件夹，将“%dir%/Navicat Liteinstantclient_10_2”路径下的所有dll文件剪切到bak文件夹）。
去Oracle客户端目录下面（..oracleproduct10.2.0client_1BIN）将以下七个dll拷贝到%dir%/Navicat Liteinstantclient_10_2下面
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oci.dll
orannzsbb10.dll
oraocci10.dll
oraocr10.dll
后面的四个好像可以不要
oraociicus10.dll
oraocrb10.dll
oraocrutl10.dll
-----------------------------------------------------------------------
重新启动navcat即可。