In addition to WSService one more protection component exist - authentication of downloads.
Microsoft will allow you to download content only on behalf of valid license signed by them.

When you start installing an app from winstore client - request goes to windows update service.
If package is in the local cache (C:\windows\softwaredistribution\download) it is used without redownloading.
Otherwise storewuauth.dll is invoked. It's purpose - return downloading URLs to windows update.
It requests WSService for license and constructs authentication tokens based on the license.
Authentication tokens are passed to microsoft as parameters. If microsoft finds them invalid it returns
http error 403 (Forbidden). Storewuauth caches authentication tokens no matter request was successfull or not
and next time you try to redownload the app uses the same bad tokens from its cache even if license
was reinstalled and now valid. That's why you will never recover from this error until you delete
storewuauth cache.
When this kind of error happens you can see error code 0x8024600e in winstore client.

Happily you can easily clean token cache. Delete this file :
C:\Windows\SoftwareDistribution\Plugins\7D5F3CBA-03DB-4BE5-B4B36DBED19A6833\117CAB2D-82B1-4B5A-A08C-4D62DBEE7782.cache

Next time you try storewuauth will have to construct new tokens and now they will be valid (if license is valid).

Please remember : without VALID MICROSOFT SIGNED license YOU CANT DOWNLOAD ANYTHING.
If you use bogus license you will fail. You have to uninstall bogus license first, clear storewuauth token cache and
get valid license. Only then you'll be able to download again.

If your trial is over see MachineID.txt. You can reset all trials.

Right idea - do not download/update through winstore client any apps you have bogus license for.
Correct way - grab appx from VM and install it without winstore.
On a VM you can try apps forever if you do things described in MachineID.txt - and without sacrificing your real LiveID.
If you still want to update through winstore - you need first uninstall your bogus license in TokenExtractor
or you'll get 0x8024600e. But dont forget about trial period. If its over you risk to leave yourself with nothing.
