So this happened to you as well. I got the notification yesterday to update my Dynamic Widgets and something didn’t go right with the update and I totally lost my dynamic widgets plugin and had to reinstall it.
This is something that has to be reported to the developer then and I will do this right now myself because I thought it was something I might have done, but turns out their update is corrupting the installed plugin. Frustrating is an understatement.
I would recommend you also post this on their plugin support page at wordpress.org too
Update: I just posted the issue I had to the plugin’s support forum. For me, my situation was slightly different from yours where my plugin was totally deleted and i had to redo everything.