If the Teamraiser Campaign is listed in the Your Selections column, the transaction may have been recorded Offline. If the receipt is not configured for 'Online and Offline transaction' or 'Offline transactions only' no receipt will generate. You can check the configuration of the receipt being used.
Once the receipt configuration has been updated to include Offline transactions, you will then have the option to Generate Receipt under the Actions column for the transaction on the Transactions tab of the constituent record. You will need to elect to 'Send receipt through built-in email' or 'Send receipt through direct mail'. After making your selection, the View Receipt option will then display under the Actions column.