On iPad, the most likely cause is that those two files are in a format Excel for iOS cannot open or can only open as read-only.
Check the file type first:
- Supported for open/edit:
.xlsx
- Supported for open/edit with limitation:
.xlsm (VBA functions will not run)
- Open read-only:
.xls, .xltx, .xlsb, .csv, .ods, .xlt
- Not supported on iOS:
.xltm, .xla, .xlam, .xml, .dif, .htm, .html, .mht, .prn, .slk, .sylk, .txt, older BIFF formats
If either file is password-protected and in an unsupported format, open it on a Windows computer and save it as .xlsx. Microsoft notes this can be a workaround, but some formatting, features, or recent changes might not be preserved.
If the files are .ods, Excel for iPad can open them only after online conversion. To edit and save:
- Tap Open in Excel on iPad.
- Browse to the file location.
- Tap the
.ods file.
- When prompted, tap Allow to let the Microsoft online service convert it.
- After it opens as read-only, tap Duplicate to save an editable
.xlsx copy.
If the files are stored in SharePoint 2010, that is a separate known issue on iPad. Use one of these methods:
- In Excel for iPad, select Add a Place.
- Choose SharePoint site URL.
- Enter the document library URL, then sign in.
Or:
- Open the SharePoint document library.
- Select Download a copy.
The date stamp change to 8/4/26 is not explained in the available documentation, but the file format and storage location are supported checks for files that suddenly stop opening while others still work.