If you see the following message in Alfresco when you try to access Salesforce content:
Something's wrong with this page...
We may have hit an error or something might have been removed or deleted, so check that the URL is correct.
Alternatively you might not have permission to view the page (it could be on a private site) or there could
have been an internal error. Try checking with your Alfresco administrator.
Check that the correct Share URL is specified in the Canvas App URL in Salesforce. See Step 3: Configure app in Salesforce for more guidance.