When updating an assembly to plugin registration - in step 2 : select the plugin and workflow activities to register, if not all plugin selected they will be deleted with their steps and images from plugin registration, is there a way to recover a plugin that was deleted, is there an XML or a file that helps recover the steps and images?
If you have earlier solution backup or take the latest solution by including the Sdk message Processing Steps from other environments & import to get the lost Plugin steps/images registration data.
Also, as an Ops guide for troubleshooting & human readable version tracker in TFS source code, I follow this on each plugin. This helped me a lot. Even if its not deployed correctly in other environments, this will help to identify the gap.
Helpful in some situation too (for future), if there is no other environments other than Dev yet.
来源：https://stackoverflow.com/questions/47889814/how-to-recover-my-plugins-data-from-plugin-registration-in-crm