File size limit is supposed to be 30MB (see articles below).  Was going to ask you to check your connection and firewall but these are unlikely the cause since it happens to both you and your client.  Suggest you contact Support when they reopen tomorrow.

https://accountants-community.intuit.com/articles/1606608-intuit-link-send-documents-to-a-client-via...

https://accountants-community.intuit.com/articles/1606402-intuit-link-upload-documents-to-send-to-th...