cant access dashboard

Using FTP or if your host provides you with any kind of file manager tool, navigate to wp-content/plugins and change the name of, or just add a prefix to, the bepro-listings directory (which will deactivate it) and you should be able to get back in after that judging by the error message being specifically related to that plugin.

Well now that you are back in your dashboard, it would be time to figure out why this happened and how to fix it before reactivating the plugin and breaking your wp-admin again. Some good things to try are listed in the link @tara kindly posted.

Were you doing anything specific before this happened? Have you updated anything recently or installed something new? Are there pending updates?