Exactly the same for me. Seems like thumbnail generation works for a limited number of protos, anything more causes this [Hacking attempt]. In previous versions it was not any problem to generate thumbnails for any number of photos!

I noticed I had spaces in some folder names. I then did a full scan and fixed all filenames. After that the multiple size generation worked. Previous to this I tried to run it about three times and they all failed with the afformentioned errors.

So, check your file names.   =]

I don't think it is anything about folders or files. It's about the number of photos in the current set!
Last night I was trying to associate photos to a virtual album - "simple" operation, when all the photos are already in the database, I suppose it has nothing to do with physical files, only with the database. Same story - when the caddie is relatively small (in my case up to 4850 photos), everything works, fast and easy. If I put more photos to the caddie - 4950 and more -  it cries about hacking attempt and does not do anything. If I remove some photos from the caddie - works well. If I put the removed photos in emty caddie - also works well. So no problems with any specific photos, just with their number. It should be somewhere in the code - if the "whole set" contains too many photos, it is hacking. Where it it? How to disable it, or temporary increase the limit?
In the end, I got what I wanted (assigned >25000 photos to a virtual album), but in many smaller bunches...

Environment
Piwigo 14.2.0 Check for upgrade
Installed on 21 January 2023, 1 year 3 weeks ago
Operating system: Linux
PHP: 8.3.2 (Show info) [2024-02-11 13:27:37]
MySQL: 8.3.0 [2024-02-11 13:27:37]
Graphics Library: ImageMagick 7.1.1-26
Cache size 11489.43 Mo   calculated 2 months ago Refresh
Activated plugin list1
LocalFiles Editor

Last edited by neon (2024-02-11 13:42:17)