In order to create a stack/ePoster in Learning Toolbox for a conference you must have activated the invite link you were sent for that conference stack/ePoster and you must have signed in using the same account you used when you activated your invite link.
If you click on Create Stack then you will see the list of the invites that you have activated (as shown in the example screenshot below).
If you do not see your ePoster invite in the list then this indicates that the account you are using does not yet have permission to create that ePoster/stack. There are two possible reasons for this:
You have not yet activated that ePoster/stack’s invite. If you are making more than one ePoster/stack for a conference then you will have been sent a separate invite email for each of your ePoster/stacks. You need to activate each one. If you have not yet activated this ePoster’s invite then find the invite email (it will have been sent to you by email@example.com) and click on the invite link and sign-in.
You activated that ePoster/stack with a different account. Sometimes authors accidentally activate their ePoster invites with different accounts (e.g. activating their first ePoster invite by signing in using Google and activating their second ePoster invite by making a local account). If you have done this by accident and you want all your invites connected to the same account then please contact your conference support team (click on Support to see the email address or look for their address on the Getting Started Page) and they should be able to sort that out for you.