I have convert product attribute from text field to text area using this query.
UPDATE eav_attribute SET frontend_input = 'textarea', backend_type = 'text' WHERE eav_attribute.attribute_code = 'out_of_stock_message';
I have run commands also run re-index command, so after that it's showing updated text area in product attribute and also in product edit page in admin panel.
But now i'm not able to save data for this product attribute and also not showing any error in error log.
Any help will be appreciated.