Meteor.js - randomly everything is 'undefined' -- why? - meteor

So I'm working on my Meteor project and all of a sudden everything stops working and my console reports that everything is 'undefined'. See screenshot. Why does this happen? Usually things will just randomly start working again after I reboot my machine or go get lunch.

This can happen if you have a hot code reload during when the page is loading from a previous hot code reload.
Your browser will eventually reconnect to the server, reconnect & refresh the page. In the case above it looks the the bit of Js that connects to the server doesn't get loaded to begin with (the DDP bit) so it doesn't behave as normal. If it reconnects it can fix it self by refreshing.
It's very hard to tell what exactly is causing it from the information you've given. I'd look at custom packages that replace core packages or some kind of of package you have that runs early on in your code that would stop the normal loading of a project.
If you're using meteor on windows there are a couple of bugs that do this too. I'm not sure how to get past those besides doing Ctrl+C to stop and then using meteor to start the project again.

Related

Visual Studio 2019 Debugger only runs once, requires restart to run again

I'm building a .net core react app. When starting the application in debug mode, I have no problems the first time I run, but if I stop debugging and attempt to run again, visual studio will stop debugging on its own as the web page is loading.
If I restart my computer, I can debug again, but if I stop and start, I experience the same issue. Restarting Visual Studio works occasionally, but it seems like I need to close out all instances of it, wait a few seconds, relaunch, wait for a few seconds after everything finishes loading, and then it will work (again, only once).
I'm assuming there's a process that isn't shutting down properly and is blocking the debugger from fully starting but I can't seem to find it. I am also running visual studio as Admin. Any help would be appreciated.
Ok so it's not a complete answer but I found what seems to be causing the issue. When the debug would fail, the URL briefly changed, showing that chrome was attempting to use the legacy browser support extension. After a bit of googling I learned that this could be caused by enabling "Javascript Debugging for ASP.NET" under Tools>Options>Debugging>General. Disabling this checkbox allows me to run debug without any issues.
Since I don't really care about the javascript debugging, this is a suitable enough answer for me, but if anyone else sees this and knows the answer that would keep javascript debugging enabled, please provide the details in case anyone needs it in the future.

Expo: "Something went wrong" immediately on start

I have used Expo a few times successfully before, but for a few days now, I am unable to get into the Expo App. Whenever I open it, I see the Expo icon for a few seconds up to even minutes, and then it redirects me to the blue "Something went wrong" screen, as if I had tried to open an app.
But I didn't! It doesn't even let me scan a QR code, it just always shows this error. If I click the back button in the app, it simply terminates. I have ensured that it is the latest version and already reinstalled it once.
It seems like it somehow had locked itself onto an old, now non-existant server, and kept at it after reinstalling the app. Here is how I solved the problem:
In the metro bundler, choose connection type "Tunnel" and copy and send the URL to your phone. If you then click on it on your phone, it should redirect to the expo app. After that it got unstuck and I could finally use it normally with the QR code again!
The tools sometimes do get locked into this state.
Close and restart all components (Expo cli, browser tabs and clients) making sure to:
Kill any stray processes on the server (you need to check Activity Monitor / Process Explorer or similar depending on your platform)
Force quit all client devices and simulators using the correct method for each platform. To verify that the client process has actually been killed, check that the app splash screen is displayed for a short while when invoking it.
Clear the Expo cache when starting again: $ expo start --clear
I ran into the same issue. Solved it by going to the left sidebar in the Metro Bundler and sending a link via email!
I've tried many of the solutions and only one worked for me (which i found trying random things). I already had 'allow display over other apps' turned on (Android/OnePlus 6t) and didn't think it had anything to do with that. But I tried this...
Close the Expo app, go the the app settings and turn off 'allow display over other apps', open the expo app and [when prompted] turn on 'allow display over other apps' again.
That seems to work in my case - at least until the next time.

ASP.NET Webpage never loading - debug from VS (2015, 2017)

I have a very strange problem I'm fighting with since VS 2015 (maybe even 2013).
Now I'm working with VS 2017 and it still occurs.
Here is the situation.
I have a legacy web application (Webforms, later enhanced by integrating webapi REST with javascript/html client code, some WCF endpoints, etc).
I build and start debug session from within VS (I do debug/testing mostly with Chrome and FF, rarely with IE/Edge/etc.), and I use IIS Express.
Most of the time the application debug session starts just fine - the page loads in browser and I can either debug server side in VS / client side in browser's debug tools.
But sometimes, the page actually never completes loading, and no matter how long I wait, it just stays locked on "loading..." message.
The only solutions I found are:
- either restart PC
- or (in Chrome), start browser in new identity.
- switch to a different browser (e.g. after starting with Chrome, open page in FF - or vice-versa).
When the page loads normally, the VS's Output Debug window displays various tracing / debug messages or progress of loading various dlls.
However, as soon as the problem described above starts to happen, the VS Output Debug starts to log msgs like
The thread <#nnnn> has exited with code 0 (0x0).
When this starts to happen, no matter what I do (except starting browser in new identity / change browser / restarting PC) I can no longer debug.
No matter if I totally close and restart the browser, clear cache, close and restart VS / IIS. Nothing helps.
The situation mentioned above occurs at very random intervals.
Sometimes I can work and debug for days (I suspend / hibernate the PC at the end of the day, resume next days, end everything works ok).
However other times the issue occur after just starting few debug sessions, and on occasions, even after a full shutdown / restart, at very first debug session, this happens.
I have lived with it for long time, but sometimes is very annoying.
Anyone have experienced a similar issue?
Any idea what is causing it, and is there is any fix / workaround?
Thank you
The messages in your output log reporting:
The thread <#nnnn> has exited with code 0 (0x0)
Just indicates that the thread has exited safely and is very normal to see this in correctly working code. In fact it would be abnormal to not see this as you will end up using all available threads.
From what you have explained I would suggest that you need to look at the extensions you have installed in your browsers. I typically will use a vanilla profile (blank profile with no modifications / extensions) so that my debugging is not affected by any modifications the extensions can make.
I would also monitor your system's CPU and memory usage. Are either of these being maxed out?

How to stop meteor.js app refreshing constantly

My relatively simple meteor app has got into the state where it refreshes constantly on load. This means you can't use the app at all. I have tried the following:
meteor reset
meteor update
reinstall meteor
restart computer
reverting to old versions of my code that are known to be good
In all cases, navigating to localhost:3000 will show the page and then immediately start a page refresh loop.
Since even very old versions show this behaviour, I am guessing it is something about meteor, not about my code but I have no idea where to start looking.
So my question is, what things might cause a meteor (1.4.1.2 and 1.4.1.3 both tried) app to get into a constant page-refresh loop?

Stuck at "Client modified--refreshing" on Terminal after Code Refresh

I installed Meteor (p.s I'm new to app developement) onto my laptop (running Windows 10) and have created an app for which I have downloaded packages for (materialize, accounts-ui and passwords). The problem that I'm facing is that whenever I make changes to the html,css or js files, I get "client-modified" on my terminal, but it never actually refreshes. It's just stuck there in a loop after no matter how many modifications I make. Is this due to the current Meteor version I have installed (1.2.1)?
=> Client modified -- refreshing
This happened to me also, yesterday and today, that's how I found this question.
My observations are:
check if the app is running and working despite the apparent hang. If it does, try making a simple change in a html or template file and see if the app auto-updates. It did for me, but your mileage may vary.
If it gets too annoying, you can always just kill and restart the app. Shouldn't take too long. Check if this improves the situation.
If 2. does not help you may try "meteor reset" to clean things up, but ONLY if you just started developing your app and don't care about losing any app data (MongoDB get's wiped along with the rest of the /.meteor/local folder)
Hope the above helps...
Norbert

Resources