Errors/Warnings/Bugs

[euler]

The syntax highlighting on the main website relies on the superb highlight.js to do it's magic. I've just updated the version and it does appear to have solved your problem. It is possible that this change will have a slight impact on the "cosmetics" with some other languages, but I hope none of those changes are harmful to the display of the code.

[justusw]

Thank you for looking into this. I can confirm that the syntax highlighting has improved.

[philiplu]

Something seems to have changed in the past couple weeks (maybe the syntax highlighting mentioned above?), but I'm seeing really long delays before a forum post has its final format. For instance, take a look at my post at the end of problem #723's forum. When I hit refresh, the MathJax mostly renders in about 6 seconds, but it's not finished. Text sizes are smaller than expected, the font is too light, and some more complicated multiline formulas (using \$\$...\$\$?) are all run together on one line.

The text then stays like that for over 2 minutes, with no sign of anything changing, even though a program monitor shows chrome.exe is very busy (one thread pegged). Finally, at 2m20s after hitting refresh, the final text format renders as expected.

This is with the latest Chrome browser running on Windows 10 (version 1909, not 2004, if that matters).

Any idea what's up?

[euler]

If you look collectively at all of the posts in that thread you will see that almost everyone has written exceptionally good posts. They include a lot of detail and a significant amount of mathematical notation. So rendering is going to take a bit of time. After the page has finished rendering and everything has settled, which takes about 5-6 seconds, I am not noticing anything unusual. I can scroll through the entire thread and everything appears to be displaying as expected; one of the formulae extends slightly beyond the post window.

At the time of posting this, I tested that thread in the latest versions of Firefox (78.0.2) and Chrome (83.0.4103.116).

As we rely on a CDN for MathJax it is possible that they were having a temporary issue when you were testing. But let's keep an eye on the situation.

[philiplu]

Thanks for the reply. The 6 second delay to render isn't surprising, but that 2+ minutes of inactivity is. I'm running the same versions of Firefox and Chrome as you. Just checked Firefox, and everything renders in about 8 seconds. But I'm currently running about 80 tabs open in Chrome (a big improvement over the 200 open tabs I had until a big purge a month or so ago ). I restarted Chrome with only PE open, and, yep, render time is about 7 seconds. So this is some interaction with either the plethora of tabs I've got open, or some other specific tab causing trouble. I'll see if I can figure out anything actionable, but it looks like this is some local problem on my side.

[shs.10978]

Hi, I am having trouble opening the thread for Problem 497. Chrome would load a few posts but when I scrolled down further, it became just a blank screen. Maths formulas were not rendered and code sections would not open.

[RobertStanforth]

Hi, I am having trouble opening the thread for Problem 497. Chrome would load a few posts but when I scrolled down further, it became just a blank screen. Maths formulas were not rendered and code sections would not open.

Thank you for reporting this. I cannot load the thread either: the Chrome tab hangs.

[jaap]

Hi, I am having trouble opening the thread for Problem 497. Chrome would load a few posts but when I scrolled down further, it became just a blank screen. Maths formulas were not rendered and code sections would not open.

Thank you for reporting this. I cannot load the thread either: the Chrome tab hangs.

I use Firefox and it gives a pop up message that the page is slowing down the browser (presumably because of MathJax), but if you let it continue it finishes loading and rendering the page, and it looks normal.

[hk]

Same problem here. (both on Chrome and Edge)
Other pages using Mathjax load perfectly. Even the second page of the forum for Problem 497 (View Problem) loads without delay.
The page hangs in the middle of the post by nhmllr.
Error code: RESULT_CODE_HUNG

[euler]

Thank you for reporting it, shs.10978. And thank you to everyone else for confirming the issue.

The problem was caused by two posts where the members had included the complete answer, which contained over 20000 digits in a code block. The syntax highlighter was having a terrible time trying to autodetect the language!

It would have made more sense to use the "collapse" tag, but I've modified the script that parses code tags to automatically convert it to a collapse tag when it displays on the page if it detects a long string of characters. This does mean that some genuine programs that contain very few spaces might now get caught by this, so we'll have to keep an eye on things. But it does mean that the page now loads properly.

[Ignis_Necrosy]

"The requested statistics page is currently unavailable" with Levels and Languages

For example, showing active members only, stats for level 5 have 7 pages. Then switch to all registered members, the stats now contain 27 pages. However, the cache doesn't seem to be updating correctly, and trying to visit page 8 to 27 produces this error.

[euler]

Thanks for reporting that error, Ignis_Necrosy. The levels summary page was not making a distinction between all and active members. There are only 629 active members at level 5, so there should only be 7 pages. I've fixed it so that the member count should be correct now.

What were you doing to get the error, "The requested statistics page is currently unavailable"?

[Ignis_Necrosy]

Thank you for looking into this. Though I probably didn't state the problem very clearly... I visited the statistics page for level 5, switched from active members to all members, then returned to that page. The member count was correct, and everything else on the page looked fine – just those hyperlinks for page 8 to 27 wouldn't actually work, they led me to this error. Maybe something caused these data to be truncated in the cache.

Correct a thing from my last post:

"The requested statistics page is currently unavailable" with Levels and Languages

As I retest it now, all statistics pages (Locations, Languages, Levels, Awards) are prone to this error.

[euler]

Thanks for persisting with it. I figured out the issue and it should all be working again now. Rather than delete all the cached data, I'll let everything update naturally, but in the meantime I've fixed level 5 right now.

For some reason I wasn't modifying the cache identifiers for the purge list with whether or not it was for all members or active members only. So when it rebuilt the cache for level 5 active members it had determined that there were 7 pages and then set about checking for the existence of any cached data beyond this. However, because the cache identifier wasn't being set correctly, it found and removed the cached data for pages 8 to 29 from the all members cache.

[Ignis_Necrosy]

Yes, it works now.

I happen to have noticed another bug: https://projecteuler.net/awards always displays member counts for all registered members even with "show active members only".

[euler]

This is all very helpful. Thank you.

It was the same issue you mentioned with the "levels" summary page. I have now double checked all of the other scripts and awards was the only other one. They should all be working as expected now.

[Ignis_Necrosy]

Thank you for the fixes.

[Thomastd]

Not really an error/warning/bug but couldn't find a different place for this;

test.PNG

I believe this highlighted "effect" should be "affect", kinda nitpicky but I'm weird that way .
Beginning programmer loving the site btw!

[euler]

You're absolutely right and I'm glad you mentioned it because I don't like having errors like that.

Interestingly, I had a look at the backup I did before the recent maintenance (30 July 2020) and I had previously used the word "affect". I was working on the back-end changes on my local machine for quite some time before uploading the changes and I recall stumbling on that phrase and deciding I wasn't happy with it. I was experimenting with using other verbs like "influence" or "impact", and even something like, "it does not have an effect on the score". It looks like I'd left it between undecided states and forgot to go back and fix it. Anyway, I've decided to change the whole sentence to the following:

Performance is a separate metric which is entirely independent of score.

On the subject of being nitpicky, I notice in your screenshot that your account link is red. That means you've not created an emergency account recovery key yet. I'd strongly recommend doing that as soon as possible, as it's the only way to recover your account if you lose/forget your password.

Good luck with the problems and I hope that you continue to enjoy them.

[Thomastd]

Glad I could help and thanks for the tip!