When you want to convert a string to a secure string with ConvertTo-SecureString, you may get the following error message
This happens when you try to convert a regular string to a secure string.
Converting to a secure string only means “to protect in memory”.
However, the standard input for the ConvertTo-SecureString cmdlet is an encrypted string.
As a workaround you can use the AsPlainText parameter, which has to be associated with the Force parameter (to confirm you understand the implications).