Can't run “gulp trust-dev-cert”. Error “cannot read ”tostring“ of null”

Question

I am trying to build up a react web part for SharePoint, and I was following the instructions from Microsoft page :

https://docs.microsoft.com/en-us/sharepoint/dev/spfx/web-parts/get-started/build-a-hello-world-web-part

On my personal PC it worked just fine, but in the office computer , whenever I try to run gulp trust-dev-cert I get this:

C:\Users\ms327\Desktop\teste>gulp trust-dev-cert Build target: DEBUG [09:19:12] Using gulpfile ~\Desktop\teste\gulpfile.js [09:19:12] Starting gulp [09:19:12] Starting 'trust-dev-cert'... [09:19:12] Starting subtask 'configure-sp-build-rig'... [09:19:12] Finished subtask 'configure-sp-build-rig' after 32 ms [09:19:12] Starting subtask 'trust-cert'... [09:19:25] Error - [trust-cert] TypeError: Cannot read property 'toString' of null [09:19:25] Error - 'trust-cert' sub task errored after 13 s Cannot read property 'toString' of null [09:19:25] 'trust-dev-cert' errored after 13 s [09:19:25] [09:19:26] ==================[ Finished ]================== Error - [trust-cert] TypeError: Cannot read property 'toString' of null Error - 'trust-cert' sub task errored after 13 s Cannot read property 'toString' of null [09:19:26] Project teste version:0.0.1 [09:19:26] Build tools version:3.9.26 [09:19:26] Node version:v8.16.0 [09:19:26] Total duration:47 s [09:19:26] Task errors:2

Have already tried to run on Node 8.*, 10.*, deleted everything I could find about node on PC to make a clean reinstall, and I cant get through it.

If I run gulp serve it works, but I cannot see my web part on SharePoint workbench.

Everything I find about this problem is related to node version. But already tried changing it several times.

even deleted .gcb-serve-data from the root folder.

Any suggestion?

what can I do to make it work?

Answer 1

You need to run it in the helloworld-webpart folder. If you have followed the instructions first you need to enter the folder

cd helloworld-webpart

Then Execute

gulp trust-dev-cert