Description:
Decided to upgrade from 6.4 to 7.2 on LUbuntu 20.04.  I edit a complicated document in MS Word 2000, document includes graphics, table of contents, complicated styles, not sure what else. If I open the doc file in LOWriter, edit, save, I can re-open it IF I have saved it somewhere on the local computer, but if I save it in a network location, I get the Format error discovered in styles.xml message box when I try to open the file again, even if I try to open the file with earlier versions of LO Writer on other machines, click OK and LOWriter disappears. The file does not appear to be recoverable after LO 7.4.1.2 saves it.  If the file is ONLY text, it works OK to save to ODT format in the network location.  I have tried several variations with no luck.  Tried setting Tools-Options-LoadSave-General-ODF format version from 1.3 Extended to 1.2 Extended, 1.2 Extended (compatability mode) and a few others, same result.  I am running MSWord2000 in Wine.  I mapped a network folder on another computer to /home/kelly/.local/share/wineprefixes/WinXP/drive_c/Appraisl and then bookmarked that folder in pcmanfm-qt to make it easy to get to.  I also have /home/kelly/.local/share/wineprefixes/WinXP/drive_c/A Work Area whcih is on my local drive, bookmarked the same way. I create or edit a doc in MSWord2000 on the local drive, save it, open in LOWriter, do a few edits not possible in Word2000 and export a PDF copy, and save the ODF version, then copy both files to the network location.  If I have to make a major revision, I usually copy the word doc back to the local drive and edit in MSWOrd2000, save it, make additional edits to the word doc in LOWriter, save as odf, export a PDF copy, and move everything back to network location (I do it that way because a file save on a 20MB+ doc in Word2000 can take several minutes, but a fraction of a second on the local drive), but if the needed revision is very minor or trivial, I will simply open the ODT on the mapped network folder in LOWriter, make the edit, save directly to the mapped network folder (which usually takes a three or four seconds), export a PDF copy to sent out, and close the odt.  The read error-sub-doc Styles.xml happens if I try to re-open that file.  If I copy that file back to the local drive, I still get that error, so the error is written into the file.  I did not get that error when I saved to the mapped network folder using the prior version, 6.4, only with the new 7.2.  I've tried everything I can think of.  It would appear that there has been some sort of bug introduced somewhere between versions 6.4 and 7.2.  Additional information:  The mapped network folder is on a second drive on a very old computer I am using as a server running an older version of Ubuntu, version 14 I think, with the root of that drive mapped to a directory in the server webroot which is on another drive which is mapped to the media directory of the boot drive.  It only does this with certain report files that I created originally in MSWord 2000 and opened with LOWriter and saved with LOWriter to a network locaiton.  It does not do this with all files, only certain larger more complex reports.  It works using LO WRiter 6.4, but saving with 7.2 corrupts the file.  Another interesting thing, if I open the word doc file in LO Writer, select all, delete, nothing left in the file, and try to save that empty file as an odt in the network folder, same thing, file read error when I try to open it again.  Sorry to bother you with this, but we need to figure this out before we try to upgrade any other installations to any newer version.  Thank you.  Kelly Trimble, Branson, Missouri.  

Steps to Reproduce:
1.described above:  map a network folder in the path of the C drive in wine
2.open or create a complicated word doc in MS Word 2000.  
3.Open the Word 2000 doc with LOWriter.
4.make any minor edit, save the file as an ODT format on the network folder mapped somewhere in the path of the C drive in Wine.  
5.close the file, exit LOWriter.
6. try to open the odt file on the network share with LOWriter

Actual Results:
message box 'Read Error. Format error discovered in the file in sub-document styles.xml' when you try to open the file saved to the network folder.  

Expected Results:
Open the file for editing.  


Reproducible: Always


User Profile Reset: No



Additional Info:
[Information automatically included from LibreOffice]
Locale: en-US
Module: TextDocument
[Information guessed from browser]
OS: Linux (All)
OS is 64bit: yes

Version: 7.4.1.2 / LibreOffice Community
Build ID: 40(Build:2)
CPU threads: 4; OS: Linux 5.15; UI render: default; VCL: gtk3
Locale: en-US (en_US.UTF-8); UI: en-US
Ubuntu package version: 1:7.4.1~rc2-0ubuntu0.20.04.1~lo1
Calc: threaded