Large Excel Workbooks Open Slow Or Fail To Open In Office 365

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I have many macro enabled Excel workbooks that I have developed over the years. These workbooks all open quickly and the macros work with no problems in Excel from Office 2010. However any workbook with a file size greater than 1.3 MB is a problem in Office 365. A file greater than 3 MB is probably not going to open at all or take so long that it eventually is listed as corrupt. The results are the same on three very different computers.


I have re-saved the test files as *.xlsb. When the file size shrinks significantly the file opens and runs as expected. Still as the xlsb file size gets above 1.3 MB, the opening slows down and the chance the file will show as corrupt increases. I have tested this repeatedly by creating test workbooks with small worksheets and VBA modules. I gradually increase the workbook size by copying the known good sheets. I save after each iteration and watch the file size for any sign ballooning that would indicate corruption.


With this and other tests, the results are consistent across all my test platforms. There is a problem in Office 365 with opening and running large macro enabled workbooks.


Has anyone else experienced this problem? Has Microsoft offered any help or a solution?

1 Reply
I have had this problem it seems to have started when i started using Office 365, still trying to find a solution!