Hello
This issue is due to NEST patch update. We had sent an email on 30th Jan with subject
[IMPORTANT] Mandatory patch for NEST Trader asking all our users to update a patch on Nest Trader. Seems like you missed that email.
You are therefore requested to check our email and update the patch in Nest trader terminal. For your convenience we've also created a
YouTube video showing how to check the Nest trader version and how to apply the patch to your Nest trader.