HTTP 500 Fehler

[Torsten62]

Liebes Forum,

seit längerem habe ich wieder mit einer alten Contao-Installation zu tun, die ich vor vielen Jahren gebastelt habe. Die Website läuft nicht mehr und ich kenne mich gar nicht mehr aus. Es könnte mit einer PHP-Umstellung (Hosteurope Mitte November. 7.4 wurde gestrichen) zu tun haben.
Ich war mir allerdings eigentlich sicher, dass ich vor einigen Monaten auf PHP 8.1 umgestellt und getestet hatte. Es müsste contao 3.5.40 installiert sein. Im letzten Fehlerlog finde ich folgendes:
Hat jemand einen Tipp für mich wie das Ding wieder ans laufen kommt? Viele Grüße Torsten

[Tue Dec 06 13:31:14 2022] [php:error] [pid 31258] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/xleet.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31259] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/takeout.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31260] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/sh3llx.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31261] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/xltavrat.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31262] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/xleet-shell.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31263] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/xlet.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31265] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/admin.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31264] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/jindex.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31272] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/xleetshell.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31275] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/sonarxleetxd.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31276] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/shell.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31277] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/xleetmailer.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31279] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/xlshell.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31278] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/.xleet.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31280] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/smx.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31281] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/orvx-shell.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31282] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/orvx.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31283] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/xl.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31284] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/lufi.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31285] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/lufix.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31286] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/payout.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31289] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/zerox.php' not found or unable to stat
[Tue Dec 06 13:31:14 2022] [php:error] [pid 31288] [client 173.212.219.29] [host diewebsite.de] script '/is/htdocs/wp11105145_FB19SI38SE/www/contao-install/locale.php' not found or unable to stat
[Tue Dec 06 15:35:40 2022] [php:error] [pid 28276] [client 10.83.12.190] [host diewebsite.de] PHP Fatal error: Array and string offset access syntax with curly braces is no longer supported in /is/htdocs/wp11105145_FB19SI38SE/www/contao-install/system/helper/mbstring.php on line 91
[Tue Dec 06 15:38:34 2022] [php:error] [pid 30254] [client 66.249.65.144] [host parkbad-gelderland.de] PHP Fatal error: Array and string offset access syntax with curly braces is no longer supported in /is/htdocs/wp11105145_FB19SI38SE/www/contao-install/system/helper/mbstring.php on line 91
[Tue Dec 06 15:43:49 2022] [php:error] [pid 1565] [client 2001:16b8:222:d900:5899:b589:2503:e0b4] [host parkbad-gelderland.de] PHP Fatal error: Array and string offset access syntax with curly braces is no longer supported in /is/htdocs/wp11105145_FB19SI38SE/www/contao-install/system/helper/mbstring.php on line 91
[Tue Dec 06 15:43:57 2022] [php:error] [pid 1665] [client 2001:16b8:222:d900:5899:b589:2503:e0b4] [host parkbad-gelderland.de] PHP Fatal error: Array and string offset access syntax with curly braces is no longer supported in /is/htdocs/wp11105145_FB19SI38SE/www/contao-install/system/helper/mbstring.php on line 91

[Spooky]

Contao 3 ist nicht mit PHP 8 kompatibel.