Hi Raju
Thanks for reaching out. There are 2 items mentioned in your description. One is the previous connections added in the DMC are missing. 2nd is the error when adding new connection. It looks something wrong with the connection profile data kept in repository database. I will let dev to take a quick look to see if any suggestion on debugging this case.
At the same time, I would recommend you to open a support case and provide related log as guided. It will be more efficient for log file transfer via support system rather than here in community.
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Su Li Hou
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