There can be various reasons for not being able to sign in. Please go through following steps and most likely you will be able to.
1. Make sure that you are using the correct link to the system which is: https://app.scandlearn.net
2. Make sure that you are using the correct email
If you don't know which one it is, contact your system administrator
3. If you can't sign in due to incorrect password, you can reset your password by clicking on the link Reset password for further instructions
4. Contact your system administrator to make sure that you have activated your account. An account is activated through an invite that has been sent out to your email and by confirming, the account will become active.
If you have not received an invite, please check your spam/trash folder.
Would it be so that you cannot find it there, please contact your system administrator and they can re-invite you.
5. Clear Cache Cookies, follow instructions in link below.
If you have any issue with any step or getting an error message please take a screenshot and send it to support@scandlearn.com so we can have a better understanding of the issue and work out a solution for you.