My spouse was granted a conditional green card which is only good for 2 years after which we were supposed to file together for the removal of conditions to secure a permanent resident status. We got divorced 6 months after the issuance of the cond. Green card. Can we remarry and file together the I-751 next year and explain that we had problems, did the divorce, but decided to get back together and work things out, or is it too late.

Thank you.

Conditional green card was automatically revoked when you divorced, so you cannot file I-751 now.

You can re-marry but to obtain LPR status for him, you would need to file a new I-130, I-485, etc. It's recommended to have experienced immigration attorney take care of this issue as USCIS may have doubt that your marriage is a sham marriage or not. You have a lot of work to do to prove that your marriage is genuine.