So, Biden dropped out and endorsed Harris. Democrats will likely have a very tough time getting their candidate's name on the ballot in Ohio (problem being the DNC late date, a problem that existed before Biden dropped out):
There are ways to resolve this problem, as two other states with early deadlines have already done. Washington state officials said they will accept a provisional certification of Biden’s nomination before the convention. And Alabama’s Legislature shortened its deadline so that Biden could qualify for the ballot there.
Neither solution seems likely in Ohio, where Republicans may be seeking to make life harder for the Democrats’ presidential nominee. The attorney general says the state can’t accept a provisional certification. And the Legislature couldn’t come up with a timely fix to the law.
Ohio laws generally take effect 90 days after passage. So a change to the deadline had to pass by May 9, but the Legislature wound up doing nothing.