Hi Sarah, Very sorry for the trouble. I have fixed this (or: I fixed one error like this, and it runs for me ;)). On macOS, If you open a Terminal, you should be able to run this: ~/xraylarch/bin/python -pip install https://urldefense.us/v3/__https://millenia.cars.aps.anl.gov/xraylarch/downl... To install this fix. FWIW, on Windows, that would be “Open a command terminal” (type “cmd” in the Start Menu’s search box). This should put you in a folder like C:\Users\yourname There should be a folder called xraylarch there. Then you can type: xraylarch\python -pip install https://urldefense.us/v3/__https://millenia.cars.aps.anl.gov/xraylarch/downl... --Matt From: Ifeffit on behalf of Sarah Bowie via Ifeffit Date: Thursday, August 1, 2024 at 7:04 AM To: ifeffit@millenia.cars.aps.anl.gov Cc: Sarah Bowie Subject: [Ifeffit] Problem with XRF mapviewer post-update Hi all, Apologies if this has already been asked elsewhere. I have previously been using XRF mapviewer with no issues on my MacBook pro (fully updated).  Larch recently prompted me to update to the newest version, and following this, XRF mapviewer ZjQcmQRYFpfptBannerStart This Message Is From an External Sender This message came from outside your organization. ZjQcmQRYFpfptBannerEnd Hi all, Apologies if this has already been asked elsewhere. I have previously been using XRF mapviewer with no issues on my MacBook pro (fully updated). Larch recently prompted me to update to the newest version, and following this, XRF mapviewer seems to be unable to open (tries and then immediately closes without any window ever opening). Oddly, all other programs in the Larch folder still work as normal. I've tried removing Larch, redownloading and reinstalling, and still have the same issue. Any suggestions would be much appreciated - I'm definitely regretting the update currently! I was also curious if there's somewhere I could just download an older Larch version? Thanks in advance, Sarah Bowie PhD student School of Environment, Geography and Geoscience University of Portsmouth, UK