Sources close to production tell TMZ ... all crew members who worked on the show that got canceled, after Barr made a racist comment on Twitter, have been contacted about returning to join "The Conners" spin-off team.

We've obtained an email sent to all the crew Thursday before ABC officially announced it was bringing back a Roseanne-free version of the show this fall. As you can see ... it's a pretty happy invite.

We're told producers especially want to get all the "Roseanne" writers back on board. Our sources say several crew members have signed back on and are excited to return ... to a fresh start.

As we reported ... "The Conners" is just a working title so far, but we're told it's getting a lot of great feedback from fans and could end up being the show's name for good.

Filming is expected to begin in late August/early September.