Klaus,
I'm beating this horse again but I've have been able to narrow this down to a 1-to-1 example that shows what is going on.
When I <include /> encrypted or un-encrypted xml ( defining the <preview> and <image> tags ) in a scene that is loaded with loadpanoscene(), before the blend to the next scene begins, there is a brief "flash" ( or occlusion of the current pano ) and then the blend begins. Subsequent visits to a scene results in correct/expected blending behavior.
In either of the links below, click as illustrated in the screen capture at the end of this message for a true comparison of the issue at hand.
This link illustrates the issue and uses <include /> to load the image XML:
https://preview.xplorit.com/orlando-florida
This is an example of the <include /> code:
<include url="https://s3-us-west-2.amazonaws.com/xplorit-media/media/pano/161051/xml_161051.xml"/
The contents of the xml_161051.xml file prior to encrypting is:
<krpano version="1.20">
<preview url="the.tiles/preview.jpg" />
<image>
<cube url="the.tiles/mres_%s/l%l/%v/l%l_%s_%v_%h.jpg" multires="512,768,1664,3200" />
</image>
</krpano>
The xml_161051.xml file being included is encrypted with krpanotools via Python scripting.
The following link blends between scenes as-expected, every time. It does not use <include /> so the <preview> and <image> elements are direct children of <scene>. This is completely a test URL. The multires settings do not match up to all of the media we use so the tiling might be a bit off, but the blending works perfectly, no "flash"/occlusion .
https://player.xplorit.com/orlando-florida
The <preview/> and <image/> code is in the following format.
<preview url="https://s3-us-west-2.amazonaws.com/xplorit-media/media/pano/161051/the.tiles/preview.jpg" />
<image>
<cube url="https://s3-us-west-2.amazonaws.com/xplorit-media/media/pano/161051/the.tiles/mres_%s/l%l/%v/l%l_%s_%v_%h.jpg" multires="512,768,1664,3200" />
</image>
Could this be an issue of relative vs. absolute reference to the media?
Immediately below is a screen capture of the file structure of the directory containing the.tiles and the .xml that is included.