Issue when activating plugin

Anyone else having problems activating the plugin? After migrating to a new webhost I’m getting this error when I try to activate.

The plugin generated 123 characters of unexpected output during activation. If you notice “headers already sent” messages, problems with syndication feeds or other issues, try deactivating or removing this plugin.

If I ignore the error then the backend of WordPress white screens when I try to view my forms, and the front end of the site also fails to load.

Strangely this all works on a cheap dreamhost, but is failing on a digital ocean ubuntu droplet.

https://www.ads-software.com/plugins/gravity-forms-stripe/