How to fix Refused to execute script from '' because its MIME type ('application/json') is not executable, and strict MIME type checking is enabled

Question

Hi,

i hope you are doing well.

I have a custom webpart written in SPFx ReactJS, when i deploy it, i have this error message :

Refused to execute script from 'https://publiccdn.sharepointonline.com/mytenant.sharepoint.com/sites/cor…-4ac6-9e8d-156baba403c4/RegionsDepartmentsComponentWebPartStrings_en-us.js' because its MIME type ('application/json') is not executable, and strict MIME type checking is enabled.

in the previous one I did not have this error message

Thanks in advance

Answer 1

Hi @AIT BAALLAL Mostafa,

I'm glad to hear you solve the problem ,if you have any issue about SharePoint, you are welcome to raise a ticket in this forum.

By the way, since the Microsoft Q&A community has a policy that "The question author cannot accept their own answer. They can only accept answers by others." and according to the scenario introduced here: Answering your own questions on Microsoft Q&A, I would make a brief summary of this thread:

Issue Symptom:

SPFx ReactJS return Refused to execute script from '' because its MIME type ('application/json') is not executable, and strict MIME type checking is enabled

Solution:

Clean and repackage the solution fixed the issue, could run following cmdlet

gulp clean --ship
gulp build --ship
gulp bundle --ship
gulp package-solution --production

You could click the "Accept Answer" button for this summary to close this thread, and this can make it easier for other community member's to see the useful information when reading this thread. Thanks for your understanding!

Answer 2

Hi @AIT BAALLAL Mostafa,

Per my research, I found out that it seems to be an error that you obtain in browser DevTools, and it's somehow related with your CSS libraries/files. You could refer to the following similar issues

https://stackoverflow.com/questions/49406057/refused-to-apply-style-from-because-its-mime-type-text-html-is-not-a-supp

https://github.com/rails/webpacker/issues/1651

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Answer 3

thank you @RaytheonXie_MSFT again

I resolve it by executing :

gulp clean --ship

gulp build --ship

gulp bundle --ship

gulp package-solution --production

Clean and --production are important, because in the last time i ignore the warning :

Warning - [package-solution] This is not a production build (--ship or --production), therefore the "includeClientSideAssets" setting will be ignored.