Troubleshooting extensions and themes

• https://support.mozilla.com/en-US/kb/Troubleshooting%20extensions%20and%20themes

Clear Cookies & Cache

• https://support.mozilla.com/en-US/kb/Template:clearCookiesCache

Clear the Network Cache

• https://support.mozilla.com/en-US/kb/How%20to%20clear%20the%20cache#w_clear-the-cache

Troubleshooting plugins

• https://support.mozilla.com/en-US/kb/Troubleshooting%20plugins

Check and tell if its working.

Opening in the side bar is the default for bookmarks that are created via a link or button on a website.
You can check the Properties of a bookmark via the right-click context menu in the side bar (Ctrl+B; Cmd+B on Mac).
In the Bookmarks Manager (Bookmarks > Show All Bookmarks) you can click the More button in the Details pane at the bottom right.
Make sure that "Load this bookmark in the side bar" is not selected.

Cor-el

Thanks; I appreciate it (and sorry for the delay). However, I think I can't have described the problem clearly enough. A bookmarked page isn't opening in a sidebar; it simply covers about a third of the screen - not every time, but quite often. Any other ideas please?

Locked or Damaged places.sqlite

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox

Check and tell if its working.

Can you attach a screenshot?

• http://en.wikipedia.org/wiki/Screenshot

Use a compressed image type like PNG or JPG to save the screenshot and make sure that you do not exceed the maximum file size (1 MB).

Cor-el

Thanks again, and again sorry for the delay.

I've now discovered how to take a screenshot, and one is shown below. The problem is spasmodic, and hasn't recurred for a few days - until today. The image normally appears at the left of my monitor screen, but the attached image is (almost) centered - because I had to drag it to be able to access the screenshot button.

Does this help you?

I had a variant of the same problem: entering a password with Neos Safekey would cause the screen to reduce to one-half or one-quarter size. no distortions or cut-offs; simply a reduced screen.

The problem was solved for me by simply re-installing the Neos.

How this might help in your situation, I dunno; but at least you're not the only one with a reduced-screen problem....

@ADG1 Did you try the links mentioned in my first reply ??

@ADG1

That looks like a "mobile" version of a webpage.

orange Firefox button (or Tools) >> Options > Content -- Enable JavaScript - hit the Advanced button
un-check Move or resize existing windows

Then restart Firefox.

Thanks

Hope you didn't think I was rude in not replying sooner. However, since the problem was arising only spasmodically, I wanted to give it a while to see whether your suggested solution worked. It appears to have done so - and I am very grateful. Thanks again.

Glad to hear it