Most, nearly all projects opened will not start when the green flag is clicked. The only way to start the project is to manually see inside and start the project scripts, and if there is, broadcast the project starting message. Usually, when green flag clicked, the project will start. But in this case, it just stays well and truly stuck on the thumbnail screen. This started at around last month and has never ended.

To reproduce:
Open a project, click the green flag, and if it stays in the thumbnail, congrats, you've reproduced the glitch.

My computer: Sony Vaio (not sure on the model/release date) made for Windows 8.1 upgraded to Windows 10
My browser / operating system: Windows NT 10.0, Chrome 84.0.4147.125, No Flash version detected

Video to the glitch:
Scratch Bug (YouTube)

wait you did that
You don’t need you machine stuff, Just browser and OS.

qrcool wrote:

wait you did that
You don’t need you machine stuff, Just browser and OS.

wonderful, that'll save my time

(To clear things up) I tried using other browsers (edge and firefox) though they didn't work as well, only in the first try

Questions:
1) Is this happens only on fullscreen? Does it happen on normal view?
2) Can you list some projects that cause this?
3) Press F12, open console, do you see any errors? (if so copy-paste here)

1. This happens anytime, no matter what screen type
2. All projects do this; the error listed was tested on this game: https://scratch.mit.edu/projects/379005860/
3. There is one critical error, the rest are warnings:
Critical:

Uncaught TypeError: Cannot read property ‘slice’ of null
at XMLHttpRequest.RequestSend (main.js:2631)
at XMLHttpRequest.xhrSendProcessor (main.js:2653)
at XMLHttpRequest.window.XMLHttpRequest.send (main.js:2562)
at XMLHttpRequest.send (projects.bundle.js:31)
at i (common.bundle.js:16)
at a (common.bundle.js:16)
at r (common.bundle.js:6)
at common.bundle.js:6
at common.bundle.js:6
at Object.get (common.bundle.js:6)
at Object.use (common.bundle.js:6)
at e.exports (common.bundle.js:6)
at projects.bundle.js:47
at common.bundle.js:38
at Object.logProjectView (projects.bundle.js:171)
at t.value (projects.bundle.js:171)
at t.n (common.bundle.js:6)
at t.i.emit (projects.bundle.js:68)
at t.<anonymous> (projects.bundle.js:146)
at t.i.emit (projects.bundle.js:68)
at t.value (projects.bundle.js:119)
at t.value (projects.bundle.js:146)
at t.value (projects.bundle.js:166)
at n (projects.bundle.js:52)
at Object.u (common.bundle.js:22)
at Object.invokeGuardedCallback (common.bundle.js:30)
at Object.invokeGuardedCallbackAndCatchFirstError (common.bundle.js:30)
at m (common.bundle.js:22)
at y (common.bundle.js:22)
at b (common.bundle.js:22)
at Array.forEach (<anonymous>)
at g (common.bundle.js:22)
at $ (common.bundle.js:22)
at Gn (common.bundle.js:30)
at Ce (common.bundle.js:22)
at batchedUpdates (common.bundle.js:22)
at Q (common.bundle.js:22)
at Le (common.bundle.js:22)

Okay, debugging:
- This is caused by project view counter; “at Object.logProjectView (projects.bundle.js:171)” is https://github.com/LLK/scratch-www/blob/develop/src/redux/preview.js#L1005
- “at Object.get (common.bundle.js:6)” is probably https://github.com/LLK/scratch-www/blob/develop/src/lib/jar.js#L52
- The XHR is at https://github.com/LLK/scratch-www/blob/develop/src/lib/jar.js#L70
- I'm not sure what “main.js” is - when I load the project page, “main.js” is not included. I guess it's browser internal and/or extensions.

Some questions:
1) do you use adblockers?
2) which browser is the crash log taken on? Chrome? Firefox?

Also:
- Press F12, Go to “Network” tab, Press the green flag, do you see an API request to an URL ending with “views”?

1. I use uBlock Origin as my adblocker
2. Chrome

There is only ‘scratch.mit.edu/svgs/project/views-gray.svg’ shown when ‘views’ is searched in the network tab (ctrl-f).

Oh and now there is an extended log of errors when green flag is pressed. This error log extends most of the HttpRequest's main.js links. When main.js link was explored a bit, it only linked into an ‘index’ script located in the project file (in this case, projects/379005860), with all the requests the website makes (then again, I am not a web/HTML developer).

Uncaught TypeError: Cannot read property ‘slice’ of null
at XMLHttpRequest.RequestSend (main.js?attr=AI9ZHjhAhRqXU75_xRfGzAGkLtzAcL8ZoxbRSfiUZZSx8SmNKRcPgqwAJThD7YyriB-Umdh41zPNkW4RIB7hBA:2631)
at XMLHttpRequest.xhrSendProcessor (main.js?attr=AI9ZHjhAhRqXU75_xRfGzAGkLtzAcL8ZoxbRSfiUZZSx8SmNKRcPgqwAJThD7YyriB-Umdh41zPNkW4RIB7hBA:2653)
at XMLHttpRequest.window.XMLHttpRequest.send (main.js?attr=AI9ZHjhAhRqXU75_xRfGzAGkLtzAcL8ZoxbRSfiUZZSx8SmNKRcPgqwAJThD7YyriB-Umdh41zPNkW4RIB7hBA:2562)
at XMLHttpRequest.send (projects.bundle.js:31)
at i (common.bundle.js:16)
at a (common.bundle.js:16)
at r (common.bundle.js:6)
at common.bundle.js:6
at common.bundle.js:6
at Object.get (common.bundle.js:6)
at Object.use (common.bundle.js:6)
at e.exports (common.bundle.js:6)
at projects.bundle.js:47
at common.bundle.js:38
at Object.logProjectView (projects.bundle.js:171)
at t.value (projects.bundle.js:171)
at t.n (common.bundle.js:6)
at t.i.emit (projects.bundle.js:68)
at t.<anonymous> (projects.bundle.js:146)
at t.i.emit (projects.bundle.js:68)
at t.value (projects.bundle.js:119)
at t.value (projects.bundle.js:146)
at t.value (projects.bundle.js:166)
at n (projects.bundle.js:52)
at Object.u (common.bundle.js:22)
at Object.invokeGuardedCallback (common.bundle.js:30)
at Object.invokeGuardedCallbackAndCatchFirstError (common.bundle.js:30)
at m (common.bundle.js:22)
at y (common.bundle.js:22)
at b (common.bundle.js:22)
at Array.forEach (<anonymous>)
at g (common.bundle.js:22)
at $ (common.bundle.js:22)
at Gn (common.bundle.js:30)
at Ce (common.bundle.js:22)
at batchedUpdates (common.bundle.js:22)
at Q (common.bundle.js:22)
at Le (common.bundle.js:22)

And another concerning problem, this time a warning.

The AudioContext was not allowed to start. It must be resumed (or created) after a user gesture on the page. <URL> (this warning logged 3012 times, which means the website tried but always failed.)

AudioContext one is unrelated.

I am checking if uBlock Origin has something to do with this. Does this happen when you disable it?

Still not sure where “xhrSendProcessor” is.

Yep, still happens when UBlock is disabled

If you click “main.js”, what file does it show? (filename and URL if possible, also source code around the place the error happened)
Example:

The video shows the file linked on the main.js stuff. The xhrSendProcesser function was located on the file showcase

Video (YouTube)

Problematic script:

Okay, this is the dangerous one: Can you disable your anti-virus software (and all browser extensions associated with it)? It looks like Kaspersky anti-virus is causing problems.

I've debugged it and this is probably a bug in the Kaspersky software.

Also, can you right click on the “main.js” tab? After that, please click open in new tab. If you can, please copy the link in the new tab.

GrahamSH wrote:

Also, can you right click on the “main.js” tab? After that, please click open in new tab. If you can, please copy the link in the new tab.

No need, I already identified the cause and it's local file.

It looks like the Kaspersky anti-virus can't uninstall without the need to sign in, due to privacy reasons so that malware can't randomly un-install the anti-virus. So, sadly i can't do anything about the anti-virus since I don't have the sign-on.