Has anyone ever implemented the update-in-place technique from Colibri Solutions?
The general outline is that the infrastructure is all in place in a deployed file and a hosted file. The deployed file is opened on the iOS device; from inside that file you hit a button to start the update script, which then does all the heavy lifting. The trick behind this technique is to start an on-timer script on the device, and then close the file on the device. The on-timer script apparently still has an existence outside the file, and keeps running. It then downloads the new file from the server, replacing the existing one on the device, and opens that new file.
I was just giving it a try and it almost works...except for one critical part. When the iOS device tries to download the new file, I get a 'file is locked or in use' error. There was one time when this worked for me earlier today - my first try of the day, whereas yesterday many attempts had failed. But I don't know what the conditions were the caused it to work, and an immediate retry failed, and has consistently failed since then.
There was an SSL error at the server that came up, before it succeeded - I just had to log in (not unexpected, although I expected a basic file login prompt, not an SSL error prompt). But this error has come up again since then, but the update has continued to fail.