"This expansion is not valid" error in software

My computer can't run the latest software so I'm temporarily using MPC Beats 2.9.1. Also, cannot use the official Expansion Builder.

I've got to the point where I'm starting to build my own expansions (which work fine in standalone mode on the hardware). But I'm having the software throw up this error when dragging the expansion (that is zipped then renamed to .xpn) into the browser of the software.

Weirdly, I get the same issue when dragging the 'official' bundled 'Trap Drums' expansion. Also, if I decompress a working official expansion, then zip it, then rename it to .xpn, it also throws up the same error.

So, for the experts, am I stuck waiting for a computer upgrade before I can successfully build expansions? Or is there a way round this?

Any help appreciated!

For XPN installers you need to include the expansion.XML file when zipping up an expansion, you make no mention of this in your post, so without any other details I would assume that's the culprit.

Not sure why you cannot use the expansion builder, you didn't detail the reasons for this. That app hasn't changed functionality since it was first included in the MPC Software eight years ago, so just grab the version that gets installed with the version of MPC Software that you are currently running and it will do all the hard work for you. The resulting XPN file will work in any version of the MPC Software from 1.7.2 onwards.

Even if you can't physically install the MPC Software, the expansion builder app can be pulled out of the installer and runs from any location, it isn't 'installed' like the main app is. This is easy to do on a Mac, probably just as easy on Windows with the right software, but as you don't state what computer OS you are on, I can't really advise further.

If you still can't use the expansion builder for some reason, just follow my guide for Force users, it makes a valid expansion without the expansion builder. And as you already know, you canzip up the folder and rename to .xpn for install in the MPC Software, although I'm not sure this is guaranteed to work in all computer OS, so YMMV. Always better to use the expansion builder.

https://www.mpc-tutor.com/akai-force-tu ... xpansions/

Oops sorry, I only just realised I haven't included any system details Running MPC Beats 2.9.1 on MacOS 10.13.6. (until I can upgrade my computer)

At some point in the last few weeks, the expansion builder has been installed to my computer, BUT its greyed out and won't launch. However you have indicated that there may be an older version I can use. I'll look into that next.

I've included the expansion.xml already, as I wanted the relevant image to show up in the hardware browser, and I've done this successfully with a few 3rd party sample libraries too. The formatting looks correct when compared to an 'official' expansion.xml. So, I can already build an expansion for the hardware, but it fails when trying to make an .xpn from. it.

Thanks for the reply, you've given me a few things to look into, I'm probably missing something really basic!

Got the expansion builder working by using the installer for MPC 2.9.1.

Thanks for the hint!