Hello!
When I opening the theme editor, this warning message regarding a code pops up and I’m unable to work on my page.
Thank you for any help in advance!
Hi, @PattyGP .
Thanks for your message, I would be happy to offer you some further insight on this. This error message is simply stating that your .css file has an error in it. Have you been customizing your coding, and if so what sort of customizations are you trying to make specifically? In order to correct this, you will need to find the specific code that the error states and revert it back to its original form. If you are having trouble doing this, I would suggest reaching out to a Shopify Expert who should be able to help guide you.
Yes, I made a couple of changes about 2 days before (about payments and look display)
But that error occurs before that and I have not been able to solve it 
Hi, @PattyGP .
It could be in relation to anything from code manipulation, to a third-party app that is affecting your coding or even a third-party theme. What theme are you using for your shop?
Venedor 1.3.0 - yellow
Hi, @PattyGP .
I would recommend testing an unpublished Shopify theme to see if the error replicates. You can do this by heading to Online Store>Themes>Free Themes>Explore free themes, choosing a Shopify theme and then select Actions on the unpublished theme:
If the issue does not replicate, this proves that you have an issue with your third-party theme and you will need to reach out to your theme’s developer for support. Just a friendly reminder, that if you manipulated the code of your theme in any way yourself, your theme’s developer may not be able to offer you assistance, if that is the case you will need to reach out to a Shopify Expert for the next steps.
I hope this information gets you on the right track for a solution, please feel free to reach back out here if you have any follow-up questions!