Please be aware that Collect url will be changing. It will become:
https://data.education.gov.uk/COLLEC.../MainPage.aspx

Please also note the note on the homepage:
Quote Originally Posted by DfE
Note that it was planned to update the Security Certificate against the new URL for COLLECT over the weekend of the 11th/12th September, but this has had to be rescheduled. The new URL has been updated to match the new Department for Education website and is https://data.education.gov.uk/COLLEC.../MainPage.aspx instead of https://data.dcsf.gov.uk/COLLECTPortalLive/login.aspx

Whilst both URL's are secure, the 'Old' URL for COLLECT (dcsf version) still has the valid Security Certificate for the time being. The Security Certificate will shortly be transferred to the new URL. In the meantime, if you have accessed the system through the new URL the system will generate a warning screen. Once the Certificate is transferred to the new URL, a warning message will be generated when using the old link in future.

Please accept our apologies for any inconvenience caused.