A few days ago, Microsoft started rolling out build 10581 of the Windows 10 Mobile Insider Preview. All builds of the Windows 10 Mobile Insider Preview are infamous for being extremely buggy and remarkably unstable, at least upon initial launch, and build 10581 was no different. Build 10581 brought with it a ton of problems and issues, and Microsoft has copped to the majority of them and even published fixes and workarounds for some of them. Among the build 10581 issues that don’t have a fix or a workaround, at least not yet, are a bunch of default storage settings and SD card information problems.
Let’s talk about the default storage settings problems first. Build 10581 of the Windows 10 Mobile Insider Preview takes away your ability to set default save locations on your Windows Phone by simply navigating to Settings > System > Storage and allocating default save locations for aspects such as applications. In fact, Settings > System > Storage will not even display the correct current default storage settings to you.
However, on the bright side, whatever default save locations you had configured on the previous build that you were using will migrate to build 10581 and will be used as the default save locations. This means that if you had your SD card set as the default save location for applications on your previous build, it will stay the same on build 10581.
If you reset your Windows Phone while on build 10581, though, your default save locations will be reverted to the system default, which is on phone. The majority of this problem only impacts your ability to change the default save locations on your Windows Phone, which is why any and all applications and data stored on both your phone storage and SD card from the previous build will not only be accessible but will also be functional on build 10581.
The other half of these problems affects the SD card info that can be accessed through the Operating System of a Windows Phone – the name of your SD card, for example. If you are using an SD card in your phone, its name will be displayed in a distorted and mangled fashion in Settings > System > Storage in build 10581. Although this bug clearly contributes to the instability of build 10581 and the fact that it still needs work, it is not actually something that renders a Windows Phone unusable and is certainly not as big as the default storage settings problem.
As of right now, even though Microsoft has admitted to the existence of these problems on build 10581 in a blog post, there are no available fixes for them. This means that all Windows 10 Mobile Insider Preview Build 10581 users can do right now is wait for patches and updates designed to fix these issues.