# Problem with previewing Latex images

• LaTeX
This forum has a problem with Latex for a long time.

1. Start writing a new post
2. Write down a Latex text in it (with "[latex ]...[/latex ]" tags)
3. Preview your Latex output (press the "Preview Post" button - No problem until now)
4. Now change your Latex text and press the "Preview Post" button again
5. On this second preview, you don't see the latest change in your Latex, you see the output of your very first edition of you Latex text

I thing this is because of browser cache. When I browse my posted topic in a different browser, I see the change, but the same browser does not update the image. I'm experiencing this problem with only this forum, the other forums has no problem with Latex. Actually, I'm previewing Latex using another forum before posting here...

jtbell
Mentor
1. Start writing a new post
2. Write down a Latex text in it (with "[latex ]...[/latex ]" tags)
3. Preview your Latex output (press the "Preview Post" button - No problem until now)
4. Now change your Latex text and press the "Preview Post" button again
5. On this second preview, you don't see the latest change in your Latex, you see the output of your very first edition of you Latex text

Step 6: hit the "refresh" or "reload page" button on your browser.

Fredrik
Staff Emeritus
Gold Member
This forum has a problem with Latex for a long time.

This is what I said in one of the other two that are currently on the first page:
There's probably 20 threads about this already, but most of them just say that the workaround is to refresh and resend after each preview. It appears that we've had this problem since April 13, 2010. According to our LaTeX guy, chroot, nothing changed on the server around that time. The problem is essentially the same in all versions of all browsers, on all operating systems. This strongly suggests that the service provider started doing some weird caching around then. Has anyone been in contact with them? Maybe Greg just needs to ask them to configure an exception.

I don't know this web stuff well enough to know if something can be done on the server. Is it possible to configure the web server software to instruct proxies to not cache images?

It seems to me that something else must be wrong, in addition to the fact that somebody is caching something. How does a transparent proxy know what image to use from the cache? Isn't the image identified by a file name or something? When I previewed these four LaTeX images, I got the two images from my previous post instead of 1 and 2, but 3 and 4 were fine.

$$1$$

$$2$$

$$3$$

$$4$$

Can someone explain how that's possible?