R 46.12 bugs are changing reports, securities

After latest update, an old Vanguard mutual fund, long closed, started showing up as having over $100k in it. If only. The financial reports also showed that and other accounts that have not been active for a few years now, and which are not in the report list I designed. Oddly, in the reports, the Vanguard fund turns negative in the last three quarters! Is there some way roll back the update to the previous version, which worked fine?