When converting Attachments to Files, Salesforce states that using “Magic Mover for Notes And Attachments to Lightning Experience” is the best approach and this is a free Appexchange app developed by Salesforce themselves.  However, there are a number of things you must be aware of before taking this knee jerk reaction, most notably, Magic Mover has a number of limitations:

1. The app is not able to convert Documents, which also need to be converted to Files for the same reasons
2. The file names of your current Attachments will be changed and if you have to change them back this will be difficult if you have many Attachments
3. The new Files created by Salesforce can only be updated or deleted via the user interface and not via apex code. Therefore, if you currently do have apex code interacting with your Attachments your code will no longer work, even if you update your code to work with Files. Or, if any of your future projects have apex code interacting with your new Files, this won’t be possible
4. If your Attachments are named with a ‘.’ in the name eg: “Architecture v 1.2.doc” you will find a strange File created by the app, the new File name will be “Architecture v 1”, which has been incorrectly named and the file type will be “2.doc” which is an invalid type

Fortunately, Metacube has already solved all of these issues and has built proprietary apex artefacts to deal with them.

If however you feel you still want to use the app built by Salesforce please read this article before installing the app because you may find the app will fail on install, or contact us to find out how we can help.