"An unexpected error occurred. PDFMaker was unable to produce the Adobe PDF."
One of my users got this error recently when she was trying to convert or combine Excel spreadsheets to PDF via the context menu. We tried removing Adobe Standard DC and reinstalling it, and then running a full repair on Office 365. When that didn't work, I disabled the COM plug-in in Excel, but I could not then *re-enable* the plug-in. So I set up a new machine also with Office 365 ProPlus (16.08431.2242) and installed Adobe Standard DC (18.011.20038), and I continue to get the "An unexpected error occurred" right away. However, if I open one Excel file and use the ribbon, the file converts just fine.
