Troubleshooting deployment and login issues with self-hosted Sanity instance

Running into some weird development and deployment issues with a self-hosted version of Sanity.So I have my studio deployed at a subdomain

<http://studio.mysite.com|studio.mysite.com>

and the site it serves content to @

<http://www.mysite.com|www.mysite.com>

.
I am using the

netlify/cli

to run a local dev instance which proxy's from a

targetPort: 3333

or the Sanity Studio application to the Netlify dev exposed

port: 9090

which is also setup as a CORS whitelisted URL on Sanity. This is supposed to mimic deployment on Netlify.
When I spin up Netlify Dev, the Studio app returns what's in the posted image, but still remains accessible at its application

port:3333

.
When it's deployed to Netlify itself, I am getting prompted for Sanity login that resolves to a

Page Not Found

message. In order to try an fix that, I have a

netlify.toml

files that does the redirects for SPA apps like so.

This still doesn't give me the expected result of being able to login to the

production

or

develop

instances of the studio app.I am bit stumped as to why this is not working as I feel I have had this setup the same way in past project tests. I have double checked all my CORS settings as well as my local configurations and still can't find a way to troubleshoot this.

Any help would be greatly appreciated.

Ok I got my production environment working by switching off my Brave browser shields. So effectively a cookie was stopping my

production

deploys, but I still can't figure out why my local Netlify Dev instance will gives me the

SyntaxError: Unexpected token '<'

Hey Jonathon. You are redirecting all requests to

/index.html

. Based on the error, I'm guessing that Sanity is trying to load a JS or JSON file, but your server is instead providing

index.html

—which is not a valid script file.
That's just a guess
🙂. Are you able to see any more details in your console about which specific request or file is leading to this error?

Hey thanks for that! I turned off the redirects and it seemed to do the trick. For some reason I was getting a

Page Not Found

on Netlify and thought this

netlify.toml

might be the solution. I guess it wasn’t….😅
Thanks again!

Alright, so after deploying without the redirects.I pulls up the login to Sanity prompt, but when I click on my preferred login method, I get whats in the image.

Kind of stumped, not sure what’s going on exactly that makes it so I cannot login to my production instances, or develop instances. All my CORS origin settings are correct.

Ahh! Cookies once again! Shoot!

The redirect is required, but I initially wondered whether it was preventing other files from being served. I just checked the Netlify docs, and this is not the case. By default, a Netlify redirect will respect existing paths .
You do need the redirect. Removing it is probably why you're now getting a

404

after signing in.
Sorry for leading you down the wrong path, but at least we've now eliminated one possible cause of this issue
🙂.
The next questions I'd like to ask are:

1. Do you have the latest version of
the Netlify CLI installed?2. Does the

SyntaxError: Unexpected token '<'

error occur both locally and on Netlify?3. Does the

SyntaxError: Unexpected token '<'

error occur when running your Studio locally using the

sanity start

command (instead of using the Netlify CLI)?

Thanks for following up . Turned out to be aggressive Cookie blocking in Brave that was the issue. Seems to be working ok now.

Great, I'm glad you got this working! And I'm sorry for the cookie issues.