Exactly what is the problem? You only have that one post, and nowhere do you state the issue you're having. If you're using a large microSD card, that's the problem. Use a small one, as close to 2 GB as you can. Or don't use one at all. They are not required. You may have received a message that suggests you install one, but a microSD card is not required.
Keep in mind, all they do is store apps onboard so the Roku doesn't have to re-download the app if space is low. When Roku devices run out of space, the device removes the oldest apps (in terms of last time used) from the device until there is enough space. All the microSD card does is increase the amount of space available for app storage. The device will not run any faster.
So, if you would state the issue that is causing you to want to add a microSD card, perhaps we can offer some suggestions specific to your Roku model number (always provide that) and any particular error message (transcribe exactly, do not paraphrase).
DBDukes Roku Community Streaming Expert Note: I am not a Roku employee.
If this post solves your problem please help others find this answer and click "Accept as Solution."
It’s a common but frustrating occurrence to read some old thread where someone linked to some (also old) piece of information, and by the time you want to read it, it’s gone.
Fortunately, the poster of that particular link also added: “Essentially repeatedly ejecting and inserting the card until it catches just right is what it took to make my Roku 3 accept my microSD Card.”