We have Excel 2007 workbooks that we regularly route through a workflow via
MOSS for digital signatures, and previously, this process worked flawlessly.
But now anytime someone signs a workbook, the next person on the workflow's
distribution list gets a message that says, "Signatures cannot be added or
removed because this read-only workbook has been changed" . . . but nobody is
making ANY editorial changes!

The only thing we've done differently is that we added some macros to this
workbook that includes some custom functions that changed the file extension
from .xlsx to .xlsm. Is that what's invalidating the electronic signatures?
This error message also says, "Remove signatures, enable editing, save your
changes, and try again," but nothing in Excel 2007's online help tells you
HOW to re-enable the editing on a signed workbook.

If both of these questions were previously answered on another thread, can
someone point me to there? Thanks.

I am not expert in all this, but i will say as i know, it is not possible to edit a document after putting your digital signature on that, because it becomes read only document. May be your digital signature are not assigned by authorized provider and that is the reason of this error.

Digital certificate

I have a similar issue. We use a service request form to authorize purchases, work orders and changes. Right now its an Excel form and has to be printed, signed, scanned and emailed by the manager to the request department.

There is also a 2nd signature required for certain situations. As you can see the process is cumbersome to say the least.

Ultimately, I would like to be able to open the form from our intranet page, complete the form and forward it by email to the manager. The problem is, when the form arrives by email and the manager tries to sign it, there is a message that says the document cannot be signed because it was opened in "read only" mode yet I can edit other portions of the document with no problem.

I have removed the Protected Mode on excel and Outlook (this would not be viable in an organization our size anyway.) but I still get the error.

Anyone know why it says read only mode and how to get around this?