# PHP error during upgrade to Nextcloud 26 **URL:** \ **Category:** ℹ️ Support\ **Tags:** php8\ **Created:** [March 22, 2023, 5:58pm UTC](https://help.nextcloud.com/t/php-error-during-upgrade-to-nextcloud-26/158331 "2023-03-22T17:58:41Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![drhans](https://help.nextcloud.com/letter_avatar/drhans/32/6_22734026db12803ebb3e059622ac3534.png) [@drhans](https://help.nextcloud.com/u/drhans)\ **Post date:** [March 22, 2023, 5:58pm UTC](https://help.nextcloud.com/t/php-error-during-upgrade-to-nextcloud-26/158331/1 "2023-03-22T17:58:41Z")
Preparing my system for an upgrade to v26 and getting this error when running ‘php --version’ after upgrading to PHP v8.1: PHP Warning: PHP Startup: Unable to load dynamic library ‘redis.so’ (tried: /us r/lib/php/20210902/redis.so (/usr/lib/php/20210902/redis.so: cannot open shared object file: No such file or directory), /usr/lib/php/20210902/redis.so.so (/usr /lib/php/20210902/redis.so.so: cannot open shared object file: No such file or d irectory)) in Unknown on line 0 ---
**Author:** ![SysKeeper](https://help.nextcloud.com/letter_avatar/syskeeper/32/6_22734026db12803ebb3e059622ac3534.png) [@SysKeeper](https://help.nextcloud.com/u/SysKeeper)\ **Post date:** [March 22, 2023, 6:21pm UTC](https://help.nextcloud.com/t/php-error-during-upgrade-to-nextcloud-26/158331/2 "2023-03-22T18:21:46Z")
Is php-redis installed for 8.1? ---
**Author:** ![drhans](https://help.nextcloud.com/letter_avatar/drhans/32/6_22734026db12803ebb3e059622ac3534.png) [@drhans](https://help.nextcloud.com/u/drhans)\ **Post date:** [March 22, 2023, 6:36pm UTC](https://help.nextcloud.com/t/php-error-during-upgrade-to-nextcloud-26/158331/3 "2023-03-22T18:36:52Z")
Do I need to reinstall php-redis specifically for 8.1? It was installed on 7.4 prior to upgrading to PHP to 8.1. How do I confirm php-redis is installed for 8.1? If it isn’t, what is the best practice method for installing it for 8.1? Thanks!! ---
**Author:** ![SysKeeper](https://help.nextcloud.com/letter_avatar/syskeeper/32/6_22734026db12803ebb3e059622ac3534.png) [@SysKeeper](https://help.nextcloud.com/u/SysKeeper)\ **Post date:** [March 22, 2023, 8:02pm UTC](https://help.nextcloud.com/t/php-error-during-upgrade-to-nextcloud-26/158331/4 "2023-03-22T20:02:16Z")
It’s a bit hard to help you, since you skipped the support template and not even knowing what OS you’re running ;-). So in general each module is specific to a PHP version. So if you install php7.4 and php7.4-mysql for example, you can’t use that mysql module for php8.1. And I guess the same problem is here for redis in your case. So if you installed php7.4-redis, you probably need php8.1-redis as well, because otherwise it won’t work. (Don’t confuse the redis module of PHP with the redis server itself, the module is just used from PHP code to connect to redis). ---
**Author:** ![wwe](https://help.nextcloud.com/user_avatar/help.nextcloud.com/wwe/32/72963_2.png) [@wwe](https://help.nextcloud.com/u/wwe)\ **Post date:** [December 14, 2024, 12:11pm UTC](https://help.nextcloud.com/t/php-error-during-upgrade-to-nextcloud-26/158331/5 "2024-12-14T12:11:08Z")