I just tried to upgrade from 6.x-1.25 to 6.x-1.26. I put the new module code in place, then tried to run the update script: white screen resulted. Looking at the PHP error log I found the following error:
Cannot redeclare _emaudio_custom_url_default_types() (previously declared in /Applications/MAMP/htdocs/test6/sites/all/modules/media_audio_flotsam/providers/custom_url.inc:12) in /Applications/MAMP/htdocs/test6/sites/all/modules/emfield/contrib/emaudio/providers/custom_url.inc on line 20
I disabled the Media Audio Flotsam module and tried again. The update script ran ok (it didn't give a white screen), but I got this error message:
The update process was aborted prematurely while running update #2 in emvideo.module. All errors have been logged. You may need to check the watchdog database table manually.
Looking at the log file, the last message was this:
http://en.localhost:8082/update.php?id=7&op=do
I think I would do better to upgrade to 6.x-2, but since it is quite different in structure, are there any special instructions for doing the upgrade?