If the upload process does not seem to progress or has stopped we recommend the following steps:
Check if you have the latest version of the app installed. If not, please update to the latest version through the app store.
Sometimes the iPhone has some difficulties in processing big amounts of data and is not able to upload the chat if there are too many other apps opened at the same time. Therefore, we recommend you to close all other apps (by double clicking on the home button and swiping up all the other apps) and to try the upload again.
Sometimes a lack of free space in the iPhone might cause the upload to stop. Please check how much memory is left on your phone. In case it is under 2 GB we recommend deleting some files in order to free some space. You can delete large videos from the galery or the temporary files from Safari.
In case it’s a very long chat with a lot of media, it might be too much for our app. Please export your chat via iCloud. How it works is explained here. 
If, after doing these steps, it still does not work please contact our support team (support@zapptales.com).