CORS errors on SPFX-projects loaded from localhost:4321 on manifests.js across multiple projects with no code changes

[KobeLiesenborgs]

Target SharePoint environment

SharePoint Online

What SharePoint development model, framework, SDK or API is this about?

💥 SharePoint Framework

Developer environment

Windows

What browser(s) / client(s) have you tested

• 💥 Internet Explorer
• 💥 Microsoft Edge
• 💥 Google Chrome
• 💥 FireFox
• 💥 Safari
• mobile (iOS/iPadOS)
• mobile (Android)
• not applicable
• other (enter in the "Additional environment details" area below)

Additional environment details

• SPFx version: tested on 1.13.1 and 1.16.1
• Node.js version: 14.15.5 and 16.18.0 respectively

Describe the bug / error

Without any code changes since last succesfull try using "gulp serve" now throws the following errors in the network tab of the browser after fully completing up to and including the reload step:

As a result the workbench can't make the webpart available. I tested this on multiple projects, across multiple tenants and have the same issue repeatedly.

Attempted resolutions: reboot system, clear both system and browser cache, renew the certificate under "gulp trust-dev-cert", manually navigating to "https://localhost:4321/temp/manifests.js" then reloading the page.

Steps to reproduce

1. Run "gulp serve"
2. Navigate to the newly opened tab based on your initialpage
3. receive the following pop-up (apologies for the dutch tenant settings)

Expected behavior

The webpart should become available in the workbench webpart selector

[Ashlesha-MSFT]

Hello @KobeLiesenborgs,
Thank you for bringing this issue to our attention. We will look into it and get back to you shortly.
If you don’t receive a reply within two working days, please use this escalation form to escalate.

[VesaJuvonen]

Hi @KobeLiesenborgs - I was just testing this with two tenants without a repro. Just checking things - but could it be that the local SSL cert has expired as that could result this kind of an exception when you then request the code from localhost.

[Ashlesha-MSFT]

@KobeLiesenborgs,
Just checking in — could you please confirm whether the issue is now resolved on your side after checking the certificate, or if you are still experiencing the CORS errors?

Thank you!

[KobeLiesenborgs]

Hi, the issues unfortunately doesn't seem to be the ssl certificate, when I manually navigate to the localhost url (https://localhost:4321) I get a valid ssl certificate as demonstrated in the browser here:

This also shows the new certificate I created as one of my debug steps last week:

[KobeLiesenborgs]

This item can be closed, after another session of "let's start from scratch" I discovered my latest chrome update has turned the setting for "local network access" off across all my profiles... re-enabling this allowed sharepoint to connect to localhost again