I’m trying to start a multisite (sub domains) installation: once stopped, Local WP is not able to start it again as it shows the message below. Please, while the team fixes this, any guidance about how to fix the issue “manually” is welcome. Bug Summary Uh-oh! Unable to start site. TypeError: Ca…

Please could you share your logs, @aerendir ? [image] Retrieve Local’s Log File A big part of troubleshooting errors, on any website or application, is the log file. This file contains a record of actions or errors that have occurred when a process is done. When reaching out for… …

Hi @nickc , attached are the logs. Thanks for your reply local-logs.zip (61.1 KB)

Thanks for these logs, @Aerendir . It’s possible your sites.json is missing port info or otherwise malformed. I’ll send you a direct message shortly so that you can share it with me if you wish, to avoid you having to share it publicly here.

@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…

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 …

Hi, @victoria.barysevich ! You can try the advice here: [image] Cannot start Local wp site Support Thanks for this report, @Joost . You can try: Removing Mailpit to force Local to copy a fresh version for you. Editing your sites.json to ensure your site is…

I followed both instructions, and nothing helped.. local-logs.zip was too big, so I extracted verbose logs to a separate archive local-logs.zip (25.6 MB) local-logs-verbose.zip (19.3 MB)

I added ports with empty WEB and SMTP arrays. After that, I started the local and problematic instance, and it started without errors

Thanks for letting us know how you solved this, @victoria.barysevich .

Multisite installation (Subdomain): Uh-oh! Unable to start site. TypeError: Cannot convert undefined or null to object

Support

nickc August 27, 2025, 8:34am 8

Hi, @victoria.barysevich! You can try the advice here:

Topic		Replies	Views
Uh-oh! Unable to start site. macos m4 Support mac	3	133	July 7, 2025
Cannot launch site/environment that worked yesterday Support mac	11	190	June 23, 2025
Cannot convert undefined or null to object Support	12	90	February 27, 2026
TypeError: Cannot convert undefined or null to object at Object Support mac	3	82	September 7, 2025
Multisite - my server is wrong for the request for subsites Bugs windows-10 , multisite	2	185	March 15, 2024

Multisite installation (Subdomain): Uh-oh! Unable to start site. TypeError: Cannot convert undefined or null to object

Related topics