Did som trial and error myself. But did not get any wiser. Seems like a totally random process. For a while I thought it was only pictures wth text wrapped around that caused the problems, but no - any could suddenly be exported as a png-resource (axel-redrum-u3899 is a typical name) when the original is a jpg-file.
So I'm stuck, really. What could I do.
Yeah, and the software is upgraded.
Do you happen to have thumbnails turned off in Plan mode? If so, try turning them on and then exporting. There is a bug in Beta 7 that has to do with inline images in rasterized (ie system font) text frames.
Alternatively, you can switch to a web safe font for text frames that have this problem.
Sorry for the inconvenience. You've encountered a bug that can occur for text frames that use system fonts (and thus will be rasterized) and contain inline graphics. In some cases the graphics will not have been loaded by Muse when the image for the text frame is generated. Thus the gray box. This bug is fixed in the official release due out next week.
You may be able to workaround this bug by opening the problem page in Design view, making a minor change (i.e. move an item and move it back) then publishing/exporting. The change (assuming you don't use undo to move the item back) will cause Muse to re-generate and re-upload or export the content for that page and since the images are all loaded in order to be displayed in the Design view the text frame images should be correctly generated.
thumbnails on, always have been.
Moving them did not do the trick either.
Do the different boxes (text and picture) have to overlap or is it enough to have system fonts on the same page? Then I'm in trouble because I have - on every page. That might explain the randomness.
So when is the official Muse out?