Avoiding "Converting Metafile" dialogs in PowerPoint Mac
Windows PowerPoint presentations that contain graphs or certain images may cause "Converting Metafile" dialogs to pop up upon opening on the Mac. How can this be avoided so that the presentations open more quickly?
This will often happen with presentations containing graphs. It happens because PowerPoint for Windows embeds graphs differently than the way PowerPoint for Mac does it.
Mac pastes graphs as Excel objects.
PowerPoint for Windows pastes/inserts graphs as embedded OLE (Object Linking & Embedding) objects. The graph data is there, but what you see on the slide is a Windows Metafile image of the graph. Windows Metafiles are fine for Windows, but PowerPoint for Mac can't display them directly. It needs to convert the graph in order to display its image on the slide.
There is, fortunately, a way to get around the problem. While on the PC (or on the Mac), open the problematic presentation and find all of the graphs.
Right-click (Control-click on the Mac) each graph, and select Grouping, Ungroup, which converts the graph to PowerPoint shapes on most occasions. With XP and up, this only removes the OLE link from each object, and leaves the Windows Metafile image. With XP and newer versions (and possibly other configurations), you need to ungroup it once again to convert the graph to PowerPoint shapes, then choose Grouping, Regroup. In any case, if you have the option to ungroup, continue doing so and then Regroup. Otherwise, the one Ungroup command should create a collection of PowerPoint shapes, at which point you can select Grouping, Group.
Warning: this detaches the graph from the original spreadsheet, so you can no longer edit the graph from within PowerPoint.
The same technique works for other OLE content (which might be images, Word tables, Excel spreadsheets or just about anything you can copy and paste from other applications in Windows). Right-click (Control-click on Mac) each one and try to Ungroup. A normal image won't allow ungrouping, but most OLE content will, so when you find one that gives you that option, ungroup. Again, especially if you are in XP or a newer version, you want to keep ungrouping until the image turns into a collection of selected PowerPoint shapes, then Regroup (or Group if that's greyed out) once.
Repeat the process for every non-PowerPoint shape that allows ungrouping.
After that, save the presentation, and you shouldn't see those dialogs any longer.
PowerPoint MVP John Reiher explains that an XL object on a slide does have some information and PPT treats it like an embedded OLE object. But what you see on the slide is a bona fide windows metafile image of the worksheet. A complex one to boot, and it takes a while to convert.
As for other metafiles, if you copy and paste a bitmap picture onto a slide, the image is pasted as a metafile, with a bitmap inside.