Uploading a revised version of published journal article on arXiv I uploaded a pre-print of an article on arXiv 1 year ago. The article was accepted in SCI journal and currently available online. However, I found a typo mistake in one equation and want to add more discussion related one figure (On researchgate I am receiving a lot of queries regarding that figure). Should i upload a new version of pre-print on arXiv? (How citations will work in this case? as arxiv version is more advanced compare to Journal version) OrI may upload a short document on arXiv as an errata/correction with extra discussion?Or I may address errata and discussion in online page of journal? Actually this journal allows the registered users to comment and start discussion related to published article.
This has happened before. Just update the arXiv version and indicate in the "Comments" field and ideally also inside the file itself that the version is newer than the published one. Examples of such updates:


https://arxiv.org/abs/0801.3306v4 (sadly, the Comments field isn't too clear here)
https://arxiv.org/abs/1605.04832v1 (here, the fact that this is a post-publication update has been made clear in the file itself)
https://arxiv.org/abs/math/0602634v4


The fact that I found/recalled these three links within 10 minutes should suggest that this is not a rare occurrence, although I wish that people would make the status of the preprint as being a more correct version of the publication clearer. Either way, the update is highly encouraged from a reader's perspective :)