Have excel close and save any open worksheets before an update.
On the last 2 updates to my iPhone, the ap called up the upgrade when I opened a worksheet. This worksheet had years of daily medical info in it. When the update came through the open spreadsheet was totally wiped clean. very bad news for me. It didn't used to do that. The update should close and save all open spreadsheets before updating.
Dan Battagin [MS XL] commented
On iPhone, your files should be auto-saved automatically. The fact that it was wiped clean sounds like a bug. We'll take a look to see if we can reproduce this on our side, and apologize for the inconvenience.
Because there isn't really a way to "close and save" apps during an update, we won't be doing this feature, but this is something that we definitely want to make sure doesn't happen in the future.