ERROR, Excel found unreadable content

Hi, I'm getting the following error when I open my .xlsb (.xlsm) file.

History of file usage:
Our Fire Fighters' Charitable Society provide nutritional snacks to elementary school kids.
Teachers submit an online form of what nutritional snacks they are requesting
-(which is where the .csv file comes from)
We import that .csv file into the spreadsheet I've created and it spits out an order sheet for Costco and delivery sheets for each of the Fire Halls to deliver the snacks to each elementary school.

I'm more than willing to share the spreadsheet if someone is willing to help me troubleshoot.

Thanks
Chris
Surrey Fire Fighters' Charitable Society
......................................................

Open with Excel 2010
"Excel found unreadable content in xxx.xlsb. Do you want to recover the contents of this workbook? If you trust the source of this workbook, click Yes"


Open with Excel 2013 (different computer)
"Excel found unreadable content in xxx.xlsb. Do you want to us to try to recover as much as we can? If you trust the source of this workbook, click Yes"

System
Windows 10 64bit Home
Office Pro Plus v2010 (v2013 on different computer)

Story:
Multi page spreadsheet that I created for importing .csv file into.
I email to a colleague for him to import data into from a seperate .csv file.
He manipulates/updates the info, saves and emails back to me.
When I open the file, I get the above error messages depending on what version of excel I open with.

He is using Excel v2013 (sometimes v2010 on a different computer)
Doesn't seem to matter what version he uses.
Error doesn't happen all the time?

There is plenty of VBA code in the spreadsheet.

History of error:
I created spreadsheet as macro saved (.xlsm), was having same issue, googled it, best suggestion was to save as .xlsb (binary). That seemed to be working for us for several months, now same error is happening with the .xlsb file. It is hit and miss with the error, some times it happens, some times not.

After opening the file by clicking YES to the question error above, it displays a windows:

Excel was able to open the file by repairing or removing the unreadable content.
Excel completed file level validation and repair. Some parts of this workbook may have been repaired or discarded.
Removed Records: Sorting from /xl/worksheets/sheet1.bin part
Click to view log file listing repairs: C:\Users\......xml

After bypassing that message, file opens and everything seems to be working.
Just unnerving knowing that maybe some data is missing?
After saving and opening again (after the "repairs") it's fine again, for a time being.


XML EDITOR of error file
<recoveryLog xmlns=//schemas.openxmlformats.org/spreadsheetml/2006/main>
<logFileName>error058040_01.xml</logFileName>
<summary>
Errors were detected in file '\Users\User\AppData\Local\Microsoft\Windows\INetCache\Content.Outlook\UPQT8829\Nutritional Orders Summary January 5 2017.xlsb'
</summary>
<additionalInfo>
<info>
Excel completed file level validation and repair. Some parts of this workbook may have been repaired or discarded.
</info>
</additionalInfo>
<removedRecords summary="Following is a list of removed records:">
<removedRecord>
Removed Records: Sorting from /xl/worksheets/sheet1.bin part
</removedRecord>
</removedRecords>
</recoveryLog>


Any help/ideas would be great!

Thanks
Chris
Surrey Fire Fighters' Charitable Society

Hello szchris384,

that error usually happens when the sheet contains some macros and/or power queries, after re-saving it everything should be fine with no data loss.

btw, to be sure you have to open the "sheet1.bin" file and check if there is any data there.

Best regards