SQL Server Error: "Unable to decrypt data"

I have two additional informations:

• the problem doesn’t occur with JDBC, only with ADO
• the problem exists only for one windows user, therefore we are checking user rights and policies

Hi @martinjaeger, this sounds similar to something we’ve seen where registry keys were the cause of the error. (FMEFORM-31224) If you submit a support case we can help guide you through this process to see if this is the case or investigate further with you. Sorry for the inconvenience!

I deleted the file c:\Users\[UserName]\AppData\Roaming\Safe Software\FME\fme_userconnection.data
This solved my problem. Then I was able to add new connections and to connect to the SQL Server database