Hi Steven
For blocking look at the picture 1.
I click on Open Gallery and the software stays like that, I close and I open on all Galleries no opens and the galleries are good.
The galleries that I open them are all on my PC.
I do not have this file look at photo 2 (C: \ Users \ Username \ Documents \ JuiceboxBuilder-Pro \ in your Windows File Explorer and, if there is a folder named .tempGallery)
I thank you for your help

Link : http://f8coy.fr/forum/JuiceboxBuilder-Pro-1.jpg

Link : http://f8coy.fr/forum/JuiceboxBuilder-Pro-2.jpg

Thank you for the additional information.
I think I understand your problem better now, thank you. (The "Open Gallery..." button on the 'Start' tab is not responsive.)

Windows Defender should not cause any problems and there have never been any reports of any interference from Windows Defender so you can safely keep Windows Defender active at all times.

The most likely cause of an "Open Gallery..." button which does not work is a persistent .tempGallery folder, as I mentioned in my last post. (A .tempGallery folder will only remain after JuiceboxBuilder-Pro is closed if there is a lock on a gallery file from another program so I recommend not editing any gallery files until after the gallery has been saved and JuiceboxBuilder-Pro has been closed.)
Your second screenshot shows the contents of the C:\Users\Username\Documents\JuiceboxBuilder-Pro\presets folder.
The .tempGallery folder (if there is one) will be inside the C:\Users\Username\Documents\JuiceboxBuilder-Pro folder alongside (not inside) the 'presets' folder. Please see the screenshot attached to this post.
Go back one level to the C:\Users\Username\Documents\JuiceboxBuilder-Pro folder and see if there is a .tempGallery folder there.

Here is another thing to try which might help.
(1) Close JuiceboxBuilder-Pro.
(2) Navigate to the C:\Users\Username\AppData\Roaming\Adobe\AIR\ELS folder.
(3) Delete the 'JuiceboxBuilder-Pro' folder inside the 'ELS' folder.
You may need to show hidden files to find and navigate inside the 'AppData' folder in Windows File Explorer.

If you continue to experience difficulties, then please try installing JuiceboxBuilder-Lite from the Juicebox-Lite zip package which you can find on the Download Page. (JuiceboxBuilder-Pro and JuiceboxBuilder-Lite can be installed and run side-by side on the same computer without interfering with each other.)
If the same problem happens with both programs, then there is likely a system-wide issue on your computer affecting both programs.
If JuiceboxBuilder-Lite works (whereas JuiceboxBuilder-Pro does not), then the problem would appear to be specific to your JuiceboxBuilder-Pro installation and a complete uninstall and reinstall (following the procedure in this forum post) should solve the problem.

One other thing that has helped another user (with a slightly different problem) was to uninstall Adobe AIR, install an older version of AIR and then upgrade AIR. Details are in this forum post.

I hope my notes above help.

That's good news. Thank you for letting me know.

I've just tried to replicate your problem again by switching between galleries in JuiceboxBuilder-Pro (without closing the program) and by opening gallery files in other programs at the same time (which I would not recommend) but I still cannot reproduce the problem you describe so I'm really not sure what the cause of your problem is.
If you can give me a detailed and specific set of steps that I can use to try to replicate your problem, I'll try again.

In the meantime, it sounds like if you edit one gallery at a time (closing and reopening JuiceboxBuilder-Pro each time) and are careful not to open any edit any gallery files in other programs whilst the gallery is open in JuiceboxBuilder-Pro, then you should hopefully be fine.

OK, please let me know if you run into any further problems.

You're welcome!

If you want to change the color and font size for just the Gallery Title, then you can do so using HTML formatting (without needing to edit the gallery's 'theme.css' file).
Please see this FAQ for details:
How do I add HTML formatting to the Gallery Title or Back Button?

For example, you could enter a Gallery Title such as the following into JuiceboxBuilder-Pro's 'Customize -> Lite -> Gallery Title' field (changing the values as appropriate):

<span style="color: #0000ff; font-size: 48px;">Gallery Title text goes here.</span>

If you really want to change the font and color for just the Gallery Title via CSS, then add the following to the foot of your gallery's 'theme.css' file (changing the values as appropriate):

/* GALLERY TITLE - LARGE SCREEN MODE */
.jb-area-large-mode-title {
    font-size: 48px !important;
    color: #0000ff !important;
}

/* GALLERY TITLE - SMALL SCREEN MODE */
.jb-idx-ssm-title-wrapper {
    font-size: 48px !important;
    color: #0000ff !important;
}