When attempting to activate Importacular, Chimpegration or Audit Trail/Validatrix if you get this error then here are some instructions that you can pass on to your IT team.
If you are feeling brave and are somewhat technical then you can follow them yourself. (You would also probably need admin rights to your own machine or the machine where you are running Raiser's Edge from).
Background (skip this if you just want the solution)
The reason that the error happens is that our hosting provider decided to make our server very secure - a bit too secure. They decided to use only the most modern ciphers for security. This meant that many slightly older machines are not able to talk to our server because they don't understand the security routines in place.
Our preferred solution is to use a tool call IISCrypto found here: https://www.nartac.com/Products/IISCrypto/
Under the cipher suites tab you will see a list of all the ciphers that are available. In order to speak to our server you need to add a few more.
Press on the highlighted button to add a new cipher. Our newly secured server only has four ciphers and you only need to ensure that one of them is present but it may be worthwhile adding the four anyway. These are shown below. Copy them and ensure that there are no leading or trailing spaces.
You will then need to press the apply button on the bottom right of the application.
You will also need to reboot the machine in order to apply the change.
When you log back in you should be able to access the change.
Note that most modern browsers have their own cipher suites. However Internet Explorer relies on Windows' own list. We have set up a page that you can try in Internet Explorer as a before and after: https://www.zeidman.info/appreg/resttest.php. It will not be able to display the page before but will after the change has been made.