Your GEDCOM import will stop when it detects one or more branches that appear to match existing profiles on Geni. When this happens, you will see a note with a "resolve" link on the GEDCOM dashboard:
You will also be sent an email informing you of the match. Clicking either the link in the email or the "resolve" link on the GEDCOM dashboard page will take you to the list of matches that must be either rejected or confirmed / merged before the import will continue:
If you prefer to not continue the import on this branch, you can click "skip" on the GEDCOM dashboard or “Skip Import” on the tree (see "What is the 'GEDCOM import in progress' icon in the tree?"). Once you skip a branch, it will be removed from the list in your GEDCOM dashboard.
Once the matches are resolved or the matching branches skipped, you will receive a notification that the import has resumed:
This process will repeat until the GEDCOM has been fully processed.