Edit October 2020: This feature is now generally rolled out, so there is no way to go back to the old format any more. From what I’ve heard, the problems described in the article below don’t occur any more.
This is just a quick heads up for the new preview feature “Store datasets in enhanced metadata format“. You should definitely think twice before turning this feature on:
With the march release came function “Store datasets in enhanced metadata format”. With this feature turned on, Power BI data models will be stored in the same format than Analysis Services Tabular models. This means that they inherit the same amazing options, that this open-platform connectivity enables.
Limitations and their consequences
But with the current setup, you could end up with a non-working file which you would have to build up from scratch for many parts. So make sure to fully read the documentation . Now!
Warning for the new enhanced metadata formatSo once you’ve stored a file with this feature turned on, there is no way to open this file in an older version of PBI Desktop where this feature is not available. So if you exchange your files with colleagues or clients who might use older versions, you should not turn this feature on.
I can hear you
You: “Well, that’s no problem for me, we’re all running on the latest version. So I’m safe to turn it on for all my files.”
Me: “So you either haven’t read until the end of the documentation, or might not have understood its consequences. At the end of the article you’ll find a list of further limitations that will not work with the new format. So if you open an existing file with the old metadata format containing one of those features, the conversion will fail and the old format will be used instead.”
You: “Well, that sounds like a good solution. Nothing can go wrong then. Why the drama, Imke?”
Me: “Imagine you work on a file that has been successfully converted and make a lot of changes to it. But after a while you realize that you need to add one of the features that are on the limitations-list. Oops… ”
So if you’re lucky, you can revert to the latest version with the old metadata format and redo your work from there. But in the worst case scenario, you have to do everything from scratch.
Well, not everything: You can clean copy the queries to a new file with just a couple of clicks (see here for example). (Hint: You don’t even need to select each folder separately. If you want to copy all queries to the other file, just select the first, hold Shift-key, select the last query and copy.)
Then you’d have to copy all your visuals one by one and redo all other settings manually.
On top of that, you’re currently running the risk to catch this bug. “Failed to save modifications to the server. Expression in partition n/a in table n/a references an unknown entity”. For me that meant that I couldn’t load any of my queries any more.
Edit 12th May 2020: If you’re getting the above error message, you’ll be able to retrieve the latest version of your pbix here: “C:\Users\<user>\AppData\Local\Microsoft\Power BI Desktop\TempSaves\Backups”. (https://community.powerbi.com/t5/Issues/Error-on-apply-Power-Query-Expression-in-partition-n-a-in-table/idc-p/1086463#M56654)
The folder for the PBI App store version can be found here: C:\Users\<UserName>\Microsoft\Power BI Desktop Store App\TempSaves\Backups
So currently I only recommend using this feature in a very controlled way and would personally not use it on files which might require further development.
Take care and stay queryious 😉