I meant to say posted in the French forum about a similar problem. The method I used is as follows.
1 I rebooted an older Intel install package.
2 It prompted an upgrade to the latest Intel version which I did
3 Ran that latest version and a pop-up appeared in the top right corner with a link offering to upgrade to the M1 version. Clicked on the M1 link and it downloaded properly and ran.
Prior to this, I reset all the java settings in System Preferences on my M1 mac mini running Big Sur.
Hope this helps. The program is now running lightning-fast.
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