I'm writing this answer as a community wiki, since the solution was provided by the OP (@Alecsou) in the comments section for visibility for the community.
The issue got resolved after refreshing the page, I investigate the error message before, and I found that it can have different causes. Some of them can be related to browser issues 1, cache and cookies, some found the issue is related to libraries, extensions, transitional issues in Google Side, etc.
For what I understand, the issue happens when Chrome (or any browser) is running making a request, and it's stop for any reason (an external or internal environment issue), which will trigger the issue.
I remember that it happened to me once, when I was working on an Apps Script code, and I took a long time coding something. It was not a long code, I was just a noob and was researching at the same time I was coding. When I finally save the code, I got the 103 error message. For my case, I think I took so long reading the documentation, and examples online so when I return to the Apps Script page, the page was white, and it took a while to show the information again. And that was the root cause of the issue for me.
Since then, I tried to save the Apps Script file every so often to make sure it doesn't happen again.
You can read more information in the following posts:
