DatamartVersionMismatch is causing much pain

[GzzztBrain]

If I edit a Datamart, make a small change, and save it, it works.

If I make a slightly bigger change and save it, it works.

If I spend hours laboriously crafting a beautiful design and save it, I get the following error and my work is lost:

I'm the only person editing the Datamart and I have only a single browser tab open.

What's causing this please? I am old, and this is not good for my heart.

[collinq · Accepted solution]

Hey @GzzztBrain ,

This is a "known issue" and part of why DataMart is not out of preview yet.  There is no workaround that I am aware of at this time.  I go back and forth with that issue as well.  You can raise an issue with Microsoft so at least your name is on the list of folks waiting for a fix.  

[GzzztBrain]

<rant>Also - this is unrelated, sorry - but I'm new to Power BI and started my learning journey with datamarts. Due to few issues like this one cropping up, I thought I'd look into using PowerBI without datamarts. And I'm like, huh, where's the product? Without datamarts, Power BI service seems essentially useless. Power BI becomes a desktop product. I say this because you can't actually build a report in Power BI service unless you paste the data into the 'Enter data' dialog or load it from Excel. You can design dataflows, sure, but you can't actually use them other than to design more dataflows. I'm having a hard time believing it and keep looking for what I missed, but nope, whatever it is that I missed, I can't find it.

On the other hand, the support for Power BI is quite hard to penetrate because the desktop and service articles are all mixed up and you never know quite what you're reading. </rant>

[collinq]

Hey @GzzztBrain ,

I understand your rant!  🙂   I think that DataMART is the answer to the issue that you bring up about DataFLOW.  For those of us having used Power BI for some time, the Datamart capability is a good thing but I see your perspective if you have expected this already.  Datamarts are going to be a great asset once they are fully cooked, but we have this frustrating time now where they *almost* work as expected.

[GzzztBrain]

Thanks. Recenty, it seems that closing the 'Loading data' dialog and refreshing the browser can successfully recover the work. There's a 'We found some unfisished work' dialog or something like that, and the edits can be reloaded and then saved without any substantive manual intervention. Not obvious to me why, if this can be done by closing the dialog and refreshing the browser, the 'Loading data' process can''t just do the same thing those steps are doing instead of throwing a DataVersionMismatch error. Anyway, at least this takes some of the heat out of it.

[Cmuglioni]

I am having exactly the same issue!! It is kind of annoying! I am considering doing the changes in powerbi desktop and then upload the entire model in a datamart....

[GzzztBrain]

Grr, it's happening any time I've done something that took effort!