Cannot restart editing on PowerPoint for iOS

The following article is in Japanese

blog.wanichan.net

But I am going to explain about this issue in English.

I have iPad mini 3 and iPod touch, and upgraded to the latest iOS and apps as well.

• iOS: 10.3.2
• PowerPoint for iOS: 2.1

for Word and for Excel for iOS, no problem to restart editing draft documents, but not for PowerPoint. When we try to open the unsaved offline presentation file from 下書き (draft) folder,

ファイルを開けません

プレゼンテーション.pptx が見つかりません。移動、名前の変更、または削除が行われた可能性があります。 

Cannot open the file

プレゼンテーション.pptx can not be found. It may have been moved, renamed, or deleted.

This problem occurs when the file name contains a voiced (゛) or semi-voiced (゜) point. For example, ピンク (pink) contains ピ (semi-voiced point) and プレゼンテーション (presentation) contains プ (semi-voiced point) and ゼ (voiced point).

That's why we cannot restart editing the presentation. Those files cannot be deleted even if we try to delete all offline presentation files from Setting > PowerPoint > Recet PowerPoint.

So unsaved files are increasing like this.