If you came across After Effects Project file that gives Expression Errors upon opening it might be that this project were created in different language. Here is why it happens and how you can fix it.
When the project is opened in a different language such as French, the name of ”Slider” becomes “Curseur”, however the expression that links to it is still looking for “Slider”. This causes the expression to not work, and produces an error message upon opening the project. This is not unique to the slider control either, all the names of expression controls will change.
There are 2 ways to make it usable form the user side. The first method is to go through each expression that links to an expression control, and change the name to it’s alternate language counterpart. You can do that for simple projects with just a few lines of expressions, but with heavy projects that uses Expression Controls all over the place this is not a convenient way to do it.
Another solution is to open the project in it’s native language. You can run After Effects CS4 in either the local language associated with the installation and activation or in English. For example, if you have the German version of After Effects CS4 installed, you can switch to English. You can switch back and forth as many times as you want. Here are step-by-step instructions for both Mac and PC users.
Mac OS X 10.5.8 and earlier (before Snow Leopard):
1. Control-click the After Effects CS4 application icon, which is in the Applications/Adobe After Effects CS4 directory.
(You can navigate to the application icon by Control-clicking the icon in the dock and choosing Show In Finder.)
2. Choose Get Info (or the equivalent, such as Informationen in German).
3. Expand the Languages (in German, Sprachen) category in the Info dialog box.
4. Deselect (uncheck) every language other than English.
5. Close the Info dialog box.
6. Double-click the application icon to start the application.
Mac OS X 10.6 Snow Leopard:
1. Right-click the AE app
2. Go to Contents/Resources/AMTLanguages/
3. Open the file that looks like: de_DE.txt in textedit
4. Change the content to en_US
5. Save the file as: en_US.txt
6. Delete the other one, or store it somewhere.
7. Now AE should start in english !
1. Open a command shell (Choose Programs > Accessories > Command Prompt).
2. Run After Effects by entering the full path to the After Effects executable file followed by the argument -L en_US.
For example, on my computers running 32-bit Windows Vista and Windows XP, here is the command that I entered to run my German copy of After Effects in English:
“C:\Program Files\Adobe\Adobe After Effects CS4\Support Files\AfterFX.exe” -L en_US
Here’s what it would be on 64-bit Windows Vista:
“C:\Program Files (x86)\Adobe\Adobe After Effects CS4\Support Files\AfterFX.exe” -L en_US
Of course, your path may be different, depending on where you installed the application.