When you want to edit files uploaded to iManage Work using Microsoft Office for the web, ensure the file you want to edit does not exceed the file size limitation set by Microsoft. If the file exceeds the file size limitation set by Microsoft, you cannot edit the file using Microsoft Office for web and the edit option is disabled.
Similarly, if you want to edit a file that is close to the file size limit set, you can open the file using Microsoft Office for the web, however, a warning is displayed. When editing, if the file size reaches the file size limit, it does not allow you to save the file back to iManage Work. However, if you make edits so that the file size reduces, then you can continue editing the file using Microsoft Office for the web.
If your edits increase the file size and exceeds the Microsoft defined limits, then we recommend that you use a desktop version of Microsoft Office.
Refer to the following article for information about the file size limits defined by Microsoft: https://docs.microsoft.com/en-us/microsoft-365/cloud-storage-partner-program/faq/file-sizes