I am applying for Ph.D. in US universities. I already applied in some places and suggested my recommenders name as well. Now one of my recommender (who previously wrote a recommendation letter for me) is unreachable. I mean I wrote her earlier and she gave me permission. Also, I had a copy of her letter which she sent me earlier. I wrote her emails but she did not respond. Now my question is can I ask the universities (where I applied) if they will accept the letter from me as my recommender is unavailable at the moment? If I have to ask, whom should I ask? The graduate program coordinator or the graduate office? Will it make a negative impact on my candidacy? (All my application papers, other two LORs have been submitted, only this one is left) Also, it is quite impossible to manage another recommender as the university is closed and the deadlines are nearer.
I would do a couple of things.
First, see if you can quickly organize a different recommender. Maybe futile, but it might work. Long term it might be useful to have a backup in any case.
Second, but simultaneously, inform the university to which you are applying that you can't reach the recommender and that Covid may be the reason. Tell them you have a copy of another letter from this person and ask for their advice on how to proceed. Give the name and email of your recommender, I think.
I suspect that people will be reasonable, given the general disruption. It shouldn't reflect badly on you if you do due diligence in getting recommendations. They may even be a bit "soft" about deadlines for such things. Note that admissions to doctoral programs is normally handled by people, not machines, and the people are all facing various kinds of disruption.
Finally, note that you not getting feedback from the recommender doesn't necessarily mean that they aren't otherwise doing their part. There may be a lot of reasons for not replying, many of them valid.