Captcha Font not Loading on PHP 8.5

[j0hax]

Describe the bug
After an Upgrade to PHP 8.5, the captcha no longer displays any text.

It appears that fonts can no longer be properly loaded.

To Reproduce
Steps to reproduce the behavior:

1. Change PHP Version to 8.5
2. Click on Preferences > CAPTCHA
3. The preview as well as actual CAPTCHAs are broken

Downgrading back to PHP 8.4 fixes the issues!

Expected behavior
CAPTCHA text is properly rendered.

Screenshots

System (please complete the following information):

• Admidio-Version 5.0.4
• PHP 8.5
• Database MySQL
• Browser Firefox
• Browser-Version 147.0.2

(Reproducible on different devices and browsers)

Additional context
Here is the related log message, warning of deprecations in PHP 8.5:

[01-Feb-2026 23:03:54 Europe/Berlin] PHP Warning:  Trying to access array offset on false in /home/web3ds8iu/html/intern.avfrisia.de/libs/securimage/securimage.php on line 2254
[01-Feb-2026 23:03:54 Europe/Berlin] PHP Warning:  imagettfbbox(): Could not find/open font in /home/web3ds8iu/html/intern.avfrisia.de/libs/securimage/securimage.php on line 2252
[01-Feb-2026 23:03:54 Europe/Berlin] PHP Warning:  Trying to access array offset on false in /home/web3ds8iu/html/intern.avfrisia.de/libs/securimage/securimage.php on line 2254
[01-Feb-2026 23:03:54 Europe/Berlin] PHP Warning:  imagettfbbox(): Could not find/open font in /home/web3ds8iu/html/intern.avfrisia.de/libs/securimage/securimage.php on line 2252
[01-Feb-2026 23:03:54 Europe/Berlin] PHP Warning:  Trying to access array offset on false in /home/web3ds8iu/html/intern.avfrisia.de/libs/securimage/securimage.php on line 2254
[01-Feb-2026 23:03:54 Europe/Berlin] PHP Warning:  imagettftext(): Could not find/open font in /home/web3ds8iu/html/intern.avfrisia.de/libs/securimage/securimage.php on line 2213
[01-Feb-2026 23:03:54 Europe/Berlin] PHP Deprecated:  Function imagedestroy() is deprecated since 8.5, as it has no effect since PHP 8.0 in /home/web3ds8iu/html/intern.avfrisia.de/libs/securimage/securimage.php on line 2448
[01-Feb-2026 23:04:06 Europe/Berlin] PHP Deprecated:  Function imagedestroy() is deprecated since 8.5, as it has no effect since PHP 8.0 in /home/web3ds8iu/html/intern.avfrisia.de/src/Infrastructure/Image.php on line 142
[01-Feb-2026 23:05:30 Europe/Berlin] PHP Deprecated:  Function imagedestroy() is deprecated since 8.5, as it has no effect since PHP 8.0 in /home/web3ds8iu/html/intern.avfrisia.de/src/Infrastructure/Image.php on line 142
[01-Feb-2026 23:07:17 Europe/Berlin] PHP Deprecated:  Function imagedestroy() is deprecated since 8.5, as it has no effect since PHP 8.0 in /home/web3ds8iu/html/intern.avfrisia.de/src/Infrastructure/Image.php on line 142
[01-Feb-2026 23:07:25 Europe/Berlin] PHP Deprecated:  Function imagedestroy() is deprecated since 8.5, as it has no effect since PHP 8.0 in /home/web3ds8iu/html/intern.avfrisia.de/src/Infrastructure/Image.php on line 303

[MightyMCoder]

@j0hax
Can you tell me your detailed captcha settings?

I tried to reproduce it with the default settings and everything seemed to work fine using the newest Admidio Version 5.0.5.

Here the settings I tested:

• Captcha type: Random character and Calculation
• Font: all available
• Width (Pixel): 215
• Number of lines: 5
• Distortion: 0.75
• Background image: none
• Background color: #FFEFC4
• Character color: #707070
• Line color: #707070
• Valid characters: 23456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghjkmnpqrstuvwxy

[blackgate2k]

I have the same problem, tested with your settings above:

[Sat Feb 21 09:49:12.059341 2026] [proxy_fcgi:error] [pid 23776:tid 23801] [remote IP address:59730] AH01071: Got error 'PHP message: PHP Warning: imagettfbbox(): Could not find/open font in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2252; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: imagettfbbox(): Could not find/open font in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2252; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: imagettfbbox(): Could not find/open font in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2252; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: imagettfbbox(): Could not find/open font in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2252; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: imagettfbbox(): Could not find/open font in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2252; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: Trying to access array offset on false in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2254; PHP message: PHP Warning: imagettftext(): Could not find/open font in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2213; PHP message: PHP Warning: imagettftext(): Could not find/open font in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2213; PHP message: PHP Warning: imagettftext(): Could not find/open font in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2213; PHP message: PHP Warning: imagettftext(): Could not find/open font in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2213; PHP message: PHP Warning: imagettftext(): Could not find/open font in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2213; PHP message: PHP Fatal error: Uncaught Error: Call to undefined function imagepng() in /var/www/domain/htdocs/libs/securimage/securimage.php:2438\nStack trace:\n#0 /var/www/domain/htdocs/libs/securimage/securimage.php(1886): Securimage->output()\n#1 /var/www/domain/htdocs/libs/securimage/securimage.php(1280): Securimage->doImage()\n#2 /var/www/domain/htdocs/libs/securimage/securimage_show.php(87): Securimage->show()\n#3 {main}\n thrown in /var/www/domain/htdocs/libs/securimage/securimage.php on line 2438', referer: https://domain/modules/preferences.php?panel=captcha

webserver /var/www/domain/htdocs # find . -name *.ttf
./update/libs/securimage/AHGBold.ttf
./update/system/fonts/AHGBold.ttf
./update/system/fonts/astigma.ttf
./update/system/fonts/indoctrine.ttf
./update/system/fonts/kingthings.ttf
./update/system/fonts/mrphone.ttf
./update/system/fonts/sorundow.ttf
./libs/securimage/AHGBold.ttf
./system/fonts/AHGBold.ttf
./system/fonts/astigma.ttf
./system/fonts/indoctrine.ttf
./system/fonts/kingthings.ttf
./system/fonts/mrphone.ttf
./system/fonts/sorundow.ttf

[Fasse]

@blackgate2k Are you also using PHP 8.5?

[blackgate2k]

@Fasse good hint, i thought I was on 8.5 too, but at the moment I have stable release PHP 8.3.29 on Linux webserver 6.12.58-gentoo with Admidio 5.0.5

[Fasse]

Since we could not reproduce that it would be important that you both describe your settings of the captcha. Or are you using the default settings?

[blackgate2k]

Hi Fasse

Most of it is default and, in my opinion, should not cause any problems.

Captcha type: random character and calculation
Font: AHGBold.ttf
Width (Pixel): 215
Number of lines: 4
Distortion: 0.75
Background image: none
Background color: #B6D6DB
Character color: #707070
Line color: #707070
Valid characters: 23456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghjkmnpqrstuvw
Captcha subtitle: none