The Xbox WASM Problem that wasn't

The recent release of the “study level” Airbus A310-300 by iniBuilds for Xbox has bought up an interesting question about whether the Xbox WASM problem was an non issue? Why couldn’t the PMDG development team not make the DC-6 work on Xbox? Why did it trigger fail safes within Xbox environment to not run?

Both aircraft are as complex in design and operation. I want to know the answer to this question.


It was answered few times in the last weeks already, apparently the WASM issue only affects third party addons.


The Airbus A310-300 was built by an addon developer for Microsoft and Asobo, it cannot be the answer why the WASM didn’t operate on the PMDG DC-6.

If this was the fix of the issue then Asobo would have helped PMDG to put it on the marketplace for Xbox.

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I posed the same question here:

I don’t get it. How does a 3rd party developing a plane for the 1st party gets it to have it work, but a 3rd party developing a plane for themselves doesn’t?


The only reason to restrict certain WASM functionality to an internal signing key or other variables is the functions can cause if abused security issues for Xbox and Microsoft and Asobo has to performs code by code checks on addon developer WASM code before signing and building the code for marketplace.

Maybe if the statement is correct, PMDG and other addon developers might not be willing to share their original code with Asobo and Microsoft for security checks for Xbox.


I had been wondering, internally, if the issue was something along these lines.

Bear in mind there’s a big difference between first party code being run (and signed) by MS, and third party addons being run in sandboxed WASM. The A310 is first party, yes it was developed by inibuilds but it was released as part of the main anniversary pack within the main sim code.

The difference with PMDG is it’s a completely 3rd party addon, so won’t be 1st party signed and will run in the WASM sandbox, hence the issues on xbox.

Problem is this would be unfeasable given the size of the marketplace, where complex addons will have thousands of lines of code. MS couldn’t guarantee security checks and would therefore have to codesign code they can’t guarantee is safe. Reviewing the code for a few aircraft developed by 3rd parties but released by MS is one thing, but for the entire marketplace quite another.


I really appreciate the perspective, here.



If it makes you feel any better, the A310 is having an issue with WASM as it is not compiling and hence the Frame rate of that module has been compromised as a result. So, maybe this is why… ie it doesn’t work properly. Check the A310 thread if you want to see what hassle this WASM on Marketplace has caused already.

The difference is the base sim vs the marketplace. The A310 was included in the base sim (even if the content was developed by a third party), whereas PMDG’s planes would be on the marketplace. And apparently that’s where the problem resides.

Because it is packaged as part of the simulation. A Microsoft product can run auxillary Microsoft code. A third party vendor, their code is not part of the signed executable, so it is an outside addon attempting to executed Auxillary code. And that is the issue. If that was allowed, malicious software could do malicious things with compiled code, so thus, it isn’t allowed.

So yes, even though these addons were written by outside vendors, they were still part of the official Microsoft product, and thus, have the right to run Microsoft code (because Microsoft has accepted that WASM code as their own).

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