What DNN Core version are you on?

It appears that Hotcakes is no longer a Module for D N N. It is now it's own CMS that is based off of D N N. If you have a version of D N N Community edition that is prior to for 8.0.3 you will be able to upgrade to Hotcakes CMS v3 with no issues. You just copy the files over and run the upgrade wizard. However, if you use Evoq or are on a version later than 8.0.3 then you will not be able to "upgrade" to Hotcakes v3 at this time.
Here is a document that talks about some of the upgrade concerns: https://hotcakescommerce....es-3-xx-from-CMS-CMS

We tried the module install on a v8.0.4 of DNN community. This is disappointing if it isn't going to be released as a module as well, we have plenty of existing sites which vary in terms of DNN versions but with it being so tightly integrated into DNN will be an issue for some. We're seeing a lot more sites on DNN 9.x now as well. We were excited to see it being open source but it's a shame if it remains as a DNN install rather than an module.

To update anyone that comes across this forum post, they changed direction a bit after the initial Open Source changes began to hit the community. There was an overwhelming level of support for the standard module-focused option and on 7/19 the Hotcakes Commerce email announcement went out to promise that a module package would be released soon.

Here's a recap of that message's content:
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Date 7/19/2017
Subject: Hotcakes Open Source Module Package Coming Soon
Message:
Last month Arrow Digital released Hotcakes for the first time under an open source license. One of the primary goals in transitioning to an open source model was to motivate as many online businesses as possible to use the Hotcakes product.

In regards to product packaging, we initially chose to only offer an integrated distribution package which included both the Hotcakes e-commerce solution as well as the CMS platform. For new users we felt that this package offered the most streamlined user experience for installation and showcased the full breadth of product features. This is the same package that is offered in the Hotcakes Cloud environment and it is the package which provides the most benefits in terms of being a fully functional e-commerce solution for the digital enterprise.

That being said, we discovered that there are many users who would like to take advantage of Hotcakes as part of their existing CMS installations. The feedback was very direct and consistent, and was shared with us through a variety of community channels. After some investigation we concluded that there was no technical reason which would prevent us from satisfying the needs of the community.

So we are very happy to announce that we will be providing a Hotcakes module package available for official download. It will be offered under the same open source license terms as the integrated Hotcakes platform. The package will be published as part of the upcoming 3.0.1 release, so please stay tuned.
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So the good news for those with existing locations and needing to perform D N N updates/upgrades, there is a version of Hotcakes coming soon which will allow that upgrade path to continue.