Before doing anything else, make a backup of your database. Then ...
Have you applied any recent updates? If so, you could try uninstalling them.
Have you tried an Office Repair (see
http://www.devhut.net/2016/09/04/how-to-repair-ms-office/)?
Have you tried Compacting your db?
Have you made any recent changes to the db?
Do you have an AutoExec Macro? If so step through the macro/code and see if it is causing the issue.
Do you have a startup form? If so, disable it and see if the db will load.
What about backups, do you have the same issue with a backup copy of your db?
Daniel Pineault, 2010-2017 Microsoft MVP
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MS Access Tips and Code Samples: http://www.devhut.net