If you are using https://pkg.go.dev/github.com/fiatjaf/eventstore/bolt (hint: unless you are running a copy of my example relay29 instance you are probably not) then you must export all your data, delete the database, then move the data back in. Because it had a bug and an update was made that isn't backwards-compatible (I could have written a migration, but it would take a long time and no one is using this anyway). It's a tedious process and honestly it's better to just delete the database and start over. Here's how you can do it (just in case there is someone out there that wants to):
wget https://github.com/fiatjaf/eventstore/releases/download/v0.6.1/eventstore
chmod +x eventstore
eventstore -t bolt -d <dbdir> query '{}' > events
rm eventstore
mv <dbdir> olddb
wget https://github.com/fiatjaf/eventstore/releases/download/v0.7.0/eventstore
chmod +x eventstore
cat events | eventstore -t bolt -d <dbdir> save