Why would my latex images look incorrect?

https://vborg.vbsupport.ru/

It should look like this:

https://vborg.vbsupport.ru/

I believe I have correctly installed the package mhchem. What else could it be?

Looks like your \ are being stripped from the formula. Can't say why.

Try using double \\

Should not be needed, tho.

How can I "Change the permissions of the pics and temp folders so the web server can write on them"?

Do you know why the latex editor looks like this? (see attachment)

This depends on the details of your hosting. Usually this can be done thoguht FTP or SSH. Ask your host.

The buttons in the editor are compiled thoguht latex. If the permissions are not set up correctly, the images for the buttons cannot be created. Fix the first point, and this will be automatically fixed as well :D

I have one question is this mod working for vBulletin 4.1.4?

I changed the permissions of the pics & temp folders but still can't see the images for the buttons!

Any idea? Please help...

edit: I found out that the editor in cms and the one @ forum are different (check the attachments).

LaTeX parsing works.

The quick-commands menu doesn't due to the new editor. If you're not using that, you're safe to go. Otherwise, I'll be working the following days on a new version to support the new editor :D

They look the same to me. The box with a red title bar is not from my mod, it's something else. The part from my mod look exactly the same in both pics.

If the permissions were not the issue, you'll have to check that you meet all the requirements of the mod (latex and the other software installed and so on).

I just want to write maths in cms and forum...

Are there any simpler ways?

I can't say what's wrong with your installation without seeing it, obviously. If you can compile the LaTeX formulas, then the images of the buttons will appear.