The KRA file is a Krita document meant as a template for watercolor paintings.
Or, to be precise, as one part for creating a template. Since @Pesi has overlooked a little but important thing while creating it¹, it would be simpler/better for you to download and use my fixed and improved version of his template instead, which you can download from the links below.
To fix the error, I have packed the files with the patterns into an easy installable bundle, in the original version the files had to be assigned by hand to the layers he designated.
The references in the KRA file I have corrected so that they now refer to the patterns installed via the bundle. This means that if you have previously installed the bundle, you will NOT have to make any assignments after you open the KRA file in Krita. The patterns are “already there” with the bundle installed and activated.:
Here is how to install it / set it up:
To be able to use the fixed template, as a template, you have to unpack/unzip the file you can download from one of my links above. It contains the two files Pesi's_-_Watercolor_Page_A5_300DPI_Needed_Pattern's.bundle and Watercolor_Page_A5_300DPI_FIXED.kra.
First, before you can open and import the KRA-File that is in the archive too, you must install the bundle via Settings → Manage Resource Libraries... and there, with a click on + Import you can browse to the bundle and import it.
Now you can open the Watercolor_Page_A5_300DPI_FIXED.kra and directly after opening this file in Krita, you have to open the menu File and click on Create Template From Current Image which will open a dialog that allows saving it as a template. There, you can give your new template a name, and if you want also a custom icon if not a generic icon is used, you can select one of the offered groups on the left or save it in an own group you create, or you can drop it into the root group which may lead to clutter on the long run when you save more templates.
From now on, you can select this template from Krita’s File → New... dialog.
Michelist
¹ He used a reference in his KRA file that points to a folder only existing on his PC, this made using his template on other PCs a difficult task.
Remove/Edit: 1 link removed