How to fix RTE in TYPO3 7 LTS for Chrome 73 (and 91)

While there has been an update for the standalone extension (compatible with TYPO3 v8) https://extensions.typo3.org/extension/rtehtmlarea/ and a TYPO3 7 ELTS release, you might be in the unlucky position that your version 8 upgrade is "just in progress" and the issue hits you hard.

For those who need a quick fix we provide the fix in multiple ways:

See the change on github

https://github.com/liayn/TYPO3.CMS/commit/15b240d849656e56b0543a645cd3e9b4345af6d5 (Updated for Chrome 91!)

Cherry-pick the change

If you are running your TYPO3 straight from a git checkout, you can simply cherry-pick the change:

git fetch "https://github.com/liayn/TYPO3.CMS.git" TYPO3_7-6 && git cherry-pick FETCH_HEAD

Apply the patch manually

Download the patch file to your server and apply the fix manually:

cd typo3_src
wget https://reelworx.at/fileadmin/Blog/Make_rtehtmleditor__RTE__compatible_with_Chrome_91.patch
patch -p0 < Make_rtehtmleditor__RTE__compatible_with_Chrome_91.patch

Apply the patch via composer

First, install the composer-patches package:

composer require cweagans/composer-patches

Then, copy the patch file provided below into patches/rte.patch of your composer installation.

Finally, add this part to your composer.json:

        "patches": {
           "typo3/cms": {
             "fix rte": "patches/rte.patch"
           }
         }

Note: This fix is only a work around to help you out quickly. We strongly advise to upgrade your TYPO3 to version 8 LTS or higher as soon as possible.

This information applies to TYPO3 7 LTS