diff --git a/.dockerignore b/.dockerignore
index ba2816f47..ec9b0741a 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -23,3 +23,15 @@ customize
 data
 datastore
 docs
+/config.js
+customization
+*.db
+/customize/
+customize
+logs
+privileged.conf
+config/config.js
+config/sso.js
+lib/plugins/*
+/onlyoffice-conf/
+/onlyoffice-dist/
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e64d67818..4d1ae54e1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,12 @@ SPDX-FileCopyrightText: 2023 XWiki CryptPad Team <contact@cryptpad.org> and cont
 SPDX-License-Identifier: AGPL-3.0-or-later
 -->
 
+# TODO next release
+
+## Upgrade notes
+
+`./install-onlyoffice.sh` is now called `/install-office.sh`. Make sure to use the new name in the future.
+
 # 🌷🩹 Spring fix release (2026.5.1)
 
 This release contains the following fixes:
diff --git a/Dockerfile b/Dockerfile
index 2d02c00c7..a3e7c07f1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -26,7 +26,7 @@ FROM node:lts-alpine
 RUN addgroup -S cryptpad -g 4001 && adduser -S cryptpad -G cryptpad --uid 4001 -h /cryptpad
 
 # Install curl for healthcheck
-# Install git, rdfind and unzip for install-onlyoffice.sh
+# Install git, rdfind and unzip for install-office.sh
 RUN apk add --no-cache ca-certificates git rdfind unzip bash curl
 
 # Copy cryptpad with installed modules
diff --git a/docker-compose.yml b/docker-compose.yml
index 868823dbe..33204dbc9 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -14,8 +14,8 @@ services:
       - CPAD_CONF=/cryptpad/config/config.js
 
       # Read and accept the license before uncommenting the following line:
-      # https://github.com/ONLYOFFICE/web-apps/blob/master/LICENSE.txt
-      # - CPAD_INSTALL_ONLYOFFICE=yes
+      # https://github.com/Euro-Office/web-apps/raw/refs/heads/main/LICENSE.txt
+      # - CPAD_INSTALL_OFFICE=yes
 
     volumes:
       - ./data/blob:/cryptpad/blob
diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
index 91defb3c4..c893b4020 100755
--- a/docker-entrypoint.sh
+++ b/docker-entrypoint.sh
@@ -30,8 +30,8 @@ fi
 
 cd $CPAD_HOME
 
-if [ "$CPAD_INSTALL_ONLYOFFICE" == "yes" ]; then
-	./install-onlyoffice.sh --accept-license --trust-repository
+if [ "$CPAD_INSTALL_ONLYOFFICE" == "yes" ] || [ "$CPAD_INSTALL_OFFICE" == "yes" ]; then
+	./install-office.sh --accept-license --trust-repository
 fi
 
 npm run build
diff --git a/install-onlyoffice.sh b/install-office.sh
similarity index 92%
rename from install-onlyoffice.sh
rename to install-office.sh
index 69d935150..3eb018cba 100755
--- a/install-onlyoffice.sh
+++ b/install-office.sh
@@ -98,8 +98,8 @@ main() {
                 rm -rf "$OO_DIR/v8/web-apps/apps/spreadsheeteditor/main/resources/help"
                 rm -rf "$OO_DIR/v8/web-apps/apps/common/main/resources/help/"
                 ;;
-            v9)  install_version v9 v9.2.0.119+5  1f1184fb04cf72a7eb2a49a9740074b5419486c79e1fd713e1f8c09b8594a826050ae941fed6ac6a96807ba73cc751d7c807bd7e6b73de9e4f8e74cd5ed04cfa ;;
-            x2t) install_x2t v7.3+1 ab0c05b0e4c81071acea83f0c6a8e75f5870c360ec4abc4af09105dd9b52264af9711ec0b7020e87095193ac9b6e20305e446f2321a541f743626a598e5318c1 ;;
+            v9)  install_version v9 v9.3.2+2 7a8b4d32b000454ac304088ba042cb6fc2007e90282b7b51bf85365e4405a33b64f7f29f5aa88628fb4b94fa1e68077c56897116b2098c8b56ec34dcdcc356df ;;
+            x2t) install_x2t v9.3.0+0 e82fbf21fcdcff2cbaca5b9a49c3a3d6bc5f5f02ba9b704a7384ceb91e17e979bf7659aaf59f677edf319fde91dd847b419e018f58f38eb1df6ab433a6cd207c ;;
             *)
                 echo "Unknown version: $version"
                 exit 1
@@ -182,8 +182,8 @@ ask_for_license() {
     ensure_command_available curl
 
     (
-        echo -e "Please review the license of OnlyOffice:\n\n"
-        curl https://raw.githubusercontent.com/ONLYOFFICE/web-apps/master/LICENSE.txt 2>/dev/null
+        echo -e "Please review the license of Euro-Office and press 'q' to continue:\n\n"
+        curl https://raw.githubusercontent.com/Euro-Office/web-apps/refs/heads/main/LICENSE.txt 2>/dev/null
     ) | less
 
     read -rp "Do you accept the license? (Y/N): " confirm &&
@@ -194,16 +194,16 @@ ask_for_license() {
 
 show_help() {
     cat <<EOF
-install-onlyoffice installs or upgrades OnlyOffice.
+install-office installs or upgrades Euro-Office.
 
 OPTIONS:
     -h, --help
             Show this help.
 
     -a, --accept-license
-            Accept the license of OnlyOffice and do not ask when running this
+            Accept the license of Euro-Office and do not ask when running this
             script. Read and accept this before using this option:
-            https://github.com/ONLYOFFICE/web-apps/blob/master/LICENSE.txt
+            https://github.com/Euro-Office/web-apps/raw/refs/heads/main/LICENSE.txt
 
     -t, --trust-repository
             Automatically configure the cloned onlyoffice-builds repository
@@ -211,7 +211,7 @@ OPTIONS:
             https://git-scm.com/docs/git-config/#Documentation/git-config.txt-safedirectory
 
     --check
-            Do not install OnlyOffice, only check if the existing installation
+            Do not install Euro-Office, only check if the existing installation
             is up to date. Exits 0 if it is up to date, nonzero otherwise.
 
     --rdfind
@@ -230,7 +230,7 @@ ensure_oo_is_downloaded() {
     ensure_command_available git
 
     if ! [ -d "$BUILDS_DIR" ]; then
-        echo "Downloading OnlyOffice..."
+        echo "Downloading Office..."
         git clone --bare https://github.com/cryptpad/onlyoffice-builds.git "$BUILDS_DIR"
     fi
     if [ ${TRUST_REPOSITORY+x} ] || [ "${PROPS[trust_repository]:-no}" == yes ]; then
diff --git a/www/common/onlyoffice/inner.js b/www/common/onlyoffice/inner.js
index 7e60bcc81..c85486aba 100644
--- a/www/common/onlyoffice/inner.js
+++ b/www/common/onlyoffice/inner.js
@@ -101,7 +101,7 @@ define([
             hashes: {},
             ids: {},
             mediasSources: {},
-            version: privateData.ooForceVersion ? Number(privateData.ooForceVersion) : OOCurrentVersion.currentVersionNumber
+            version: privateData.ooForceVersion ? Number(privateData.ooForceVersion) : OOCurrentVersion.currentVersionNumber,
         };
         content.originalVersion = content.version;
         var oldHashes = {};
@@ -2252,6 +2252,11 @@ define([
                 }];
                 common.checkTrimHistory(channels);
             }
+
+            content.debug = content.debug ?? {};
+            content.debug.idCollision = content.debug.idCollision ?? false;
+            APP.onLocal();
+
             console.log("OO ready");
         };
 
@@ -2674,12 +2679,25 @@ Uncaught TypeError: Cannot read property 'calculatedType' of null
                 makeChannel();
                 return;
             }
+
+            const onCorruptionWarning = Util.once((id) => {
+                console.log('id collision in document', id);
+                if (content?.debug?.idCollision !== undefined // No feedback for old documents
+                    && content?.debug?.idCollision === false) { // Send feedback only once
+                    Feedback.send(`channel=${content.channel}&OFFICE_DOCUMENT_ID_COLLISION`, true);
+                    content.debug = content.debug ?? {};
+                    content.debug.idCollision = true;
+                    APP.onLocal();
+                }
+            });
+
             APP.docEditor.connectMockServer({
                 onMessage: fromOOHandler,
                 getParticipants: getParticipants,
                 onAuth: onAuth,
                 getImageURL: getImageURL,
                 getInitialChanges: getInitialChanges,
+                onCorruptionWarning: onCorruptionWarning,
             });
         };
 
@@ -3047,7 +3065,7 @@ Uncaught TypeError: Cannot read property 'calculatedType' of null
             pinImages();
         };
 
-        const loadCp = async function (cp, keepQueue) {
+        const loadCheckpoint = async function (cp, keepQueue) {
             if (!isLockedModal.modal) {
                 isLockedModal.modal = UI.openCustomModal(isLockedModal.content);
             }
@@ -3098,7 +3116,7 @@ Uncaught TypeError: Cannot read property 'calculatedType' of null
                 });
                 ooChannel.historyLastHash = ooChannel.lastHash;
                 ooChannel.currentIndex = ooChannel.cpIndex;
-                loadCp(lastCp, true);
+                loadCheckpoint(lastCp, true);
             }).catch(err => {
                 console.error(err);
             });
@@ -3268,7 +3286,7 @@ Uncaught TypeError: Cannot read property 'calculatedType' of null
                 };
                 var onCheckpoint = function (cp) {
                     // We want to load a checkpoint:
-                    loadCp(cp);
+                    loadCheckpoint(cp);
                 };
                 var onPatchBack = function (cp, msgs) {
                     if (msgs) {
@@ -3285,10 +3303,10 @@ Uncaught TypeError: Cannot read property 'calculatedType' of null
                         });
                         ooChannel.queue = msgsFormatted;
                         setTimeout(function () {
-                            loadCp(cp, true);
+                            loadCheckpoint(cp, true);
                         }, 200);
                     } else {
-                        loadCp(cp);
+                        loadCheckpoint(cp);
                     }
                 };
                 var setHistoryMode = function (bool) {
@@ -3308,7 +3326,7 @@ Uncaught TypeError: Cannot read property 'calculatedType' of null
 
                     rtChannel.getHistory(function () {
                         var lastCp = getLastCp();
-                        loadCp(lastCp, true);
+                        loadCheckpoint(lastCp, true);
                     });
                 };