@nickc , I just sent you the sites.json file. I also added other info.
For the casual reader of this post, the main thing to keep in mind is: it may be possible the site can start completely closing Local WP and then reopening it.
Thanks for the sites.json file, @Aerendir. For others, it showed missing ports for the Mailpit service, which would cause the “Cannot convert undefined or null to object” error you saw.
So far I haven’t been able to reproduce missing Mailpit ports after stopping a site, but I’ll leave this open for now in case others encounter it.
Thank you for posting your workaround here to stop and restart Local should people see this.
Hi! I faced the same issue.. It happens right after I try to turn on Xdebug.. Local restart and computer restart don’t help. site.json is missing the ports, but I don’t know how to fix it. It strangely happens to fresh instances only. I have xdebug turned on on some another website. Let me know how can I help you investigate it