/Tools/Share Document, check "share document with other users", ok
If file is originally .ods with "shared document" enabled, saving as XLSX loses the shared status.
If file is originally .xlsx, the shared status is lost when the document is closed; also, any saving of the document while open (where it claims as shared), tries to save as non-shared and asks to merge manually with original "shared" document, which is the document open...
Arch Linux 64-bit, KDE Plasma 5
Build ID: c13f60e7cd18df6b0ab70289f5b91ee01e4ae126
CPU Threads: 8; OS Version: Linux 4.6; UI Render: default;
Locale: fi-FI (fi_FI.UTF-8)
Built on June 18th 2016
Could you please attach some .xlsx and .odt documents on which it is possible to reproduce this issue?
Created attachment 127839 [details]
ODS with shared status
Save this as XLSX and observe the title bar drop (shared)
Then you can set the XLSX to shared mode and try saving it.
You will get an error dialog:
This spreadsheet is no longer in shared mode.
Save your spreadsheet to a separate file and merge your changes to the shared spreadsheet manually.