Data loss in Salesforce can be caused by a number of reasons, including :
* Changing data and date-time.
* Migrating to percent, number, and currency from other data types.
* Changing from the multi-select picklist, checkbox, auto number to other types.
* Altering to multi-select picklist from any type except picklist.
* Changing to auto-number except for text.
* Changing from text-area to e-mail, phone, URL, and text.
