Ubuntu 26.04: Word, Excel, and Searchable PDF Export

The current release runs on Ubuntu 26.04, but Word, Excel, and searchable PDF export have a runtime compatibility limitation and need an extra launch setting. Ubuntu 22.04 / 24.04 do not need this setting.

Understand the security impact first

glibc.rtld.execstack=2 forces an executable stack at process startup to accommodate dynamically loaded modules that require it. This reduces stack execution protection for the affected process; it is not a security-neutral performance option.

Apply it only when starting CZUR Image+. Child processes may inherit the environment. Do not add it to /etc/environment, shell-wide configuration, or other environment settings that affect all applications. Follow your organization's security policy on managed computers.

Option 1: verify from a terminal

Completely exit CZUR Image+, including any instance running in the background, then launch it as a regular user:

env GLIBC_TUNABLES=glibc.rtld.execstack=2 /opt/apps/com.czur.imageplus/CZURImagePlus

Closing a window may not fully exit the application. Use its exit action. Otherwise, the new command might only bring an old instance to the foreground without changing that instance's environment.

This command assumes the default installation path. If you already set other GLIBC_TUNABLES, preserve them and combine the required key/value settings with colons rather than overwriting them.

Option 2: create a per-user desktop launcher

After the terminal check succeeds, modify a per-user .desktop copy instead of changing system installation files.

1. The default system launcher is /usr/share/applications/com.czur.imageplus.desktop. If your package uses a different name, use its actual file.

2. Create the user application directory, then copy only if the destination does not already exist:

   mkdir -p "${XDG_DATA_HOME:-$HOME/.local/share}/applications"
   cp -n /usr/share/applications/com.czur.imageplus.desktop \
     "${XDG_DATA_HOME:-$HOME/.local/share}/applications/com.czur.imageplus.desktop"

   Do not overwrite an existing user copy. Back it up before editing it with a text editor.

3. Find Exec=. If it already uses env, insert GLIBC_TUNABLES=glibc.rtld.execstack=2 after env. Otherwise prefix the existing command with env GLIBC_TUNABLES=glibc.rtld.execstack=2.

4. Preserve existing environment variables, paths, options, and %F / %U arguments. This is a minimal example, not a replacement for a line containing additional required settings:

   Exec=env GLIBC_TUNABLES=glibc.rtld.execstack=2 /opt/apps/com.czur.imageplus/CZURImagePlus

   If the original launcher uses %U, keep it:

   Exec=env GLIBC_TUNABLES=glibc.rtld.execstack=2 /opt/apps/com.czur.imageplus/CZURImagePlus %U

5. Save the file and restart the system. Then launch CZUR Image+ from the Applications menu. Desktop copies and pinned icons may still point to the original file; check which launcher is actually used.

Option 3: edit the system desktop launcher

You can also edit the package's .desktop file directly. This requires administrator permissions and affects all users who use that system launcher. Software updates may overwrite the change. Choose either option 2 or option 3.

1. Back up the original file first:

   sudo cp -n /usr/share/applications/com.czur.imageplus.desktop /usr/share/applications/com.czur.imageplus.desktop.bak

   If .bak already exists, do not overwrite it. Use another backup filename to preserve the current file before editing.

2. Open the system launcher:

   sudo vim /usr/share/applications/com.czur.imageplus.desktop

3. Edit Exec=. For the default installation path:

   Exec=env GLIBC_TUNABLES=glibc.rtld.execstack=2 CZ_SCAN_RES_DIR=/opt/apps/com.czur.imageplus LD_LIBRARY_PATH=/opt/apps/com.czur.imageplus /opt/apps/com.czur.imageplus/CZURImagePlus

   The main change is to prefix the existing launch command with env GLIBC_TUNABLES=glibc.rtld.execstack=2. If the line already uses env, add only GLIBC_TUNABLES=glibc.rtld.execstack=2 after it; do not add a second env. Preserve CZ_SCAN_RES_DIR, LD_LIBRARY_PATH, other environment settings, launch options, and %F / %U arguments. If other GLIBC_TUNABLES are already set, combine them with colons instead of overwriting them.

4. Save the file and restart the system. Then launch CZUR Image+ from the Applications menu. Use sudo only to edit the file, not to run the application.

A per-user launcher with the same name takes precedence over the system file. Edit the launcher actually in use; desktop copies and pinned icons may also retain old settings.

Verify the result

1. Import a clear image containing text.
2. Export Word (DOCX), open it in a compatible editor, and inspect the content.
3. Export Excel, open it in a compatible editor, and inspect the content.
4. Export searchable PDF, search for a known word, and check text selection or copying.
5. If using file-manager integration, test that entry point as well to check that launcher arguments were preserved.

If it still fails, do not relax other system security settings. Keep the OS version, Image+ version, export format, and error details; follow feedback preparation.

Undo the change

Remove the added key/value setting from the edited Exec=, preserving other environment settings, or restore your backup. Option 3 requires administrator permissions to edit the system launcher or restore its backup. If you created a new user copy for this workaround, removing it restores use of the system launcher; if the system launcher was also modified, undo that change separately. Do not delete system installation files. Fully exit and relaunch the application afterwards.

Check again after software updates. This note does not imply that future releases will permanently need an executable stack.

References: GNU C Library dynamic linking tunables and Desktop Entry Specification.

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Documentation updated: October 19, 2026. Applies to the current Linux Debian package; refer to the release package for its exact version and architecture.