I believe this is a Mac error. You will want to make sure that Word’s Startup folder, (Word menu / Preferences / File Locations), is pointing to the right area (Applications / Microsoft Office 20xx / Office / Startup / Word).
Once that is done, you will want to make sure that only EndNote X5’s tools are in that startup folder. Close out of Word and EndNote entirely. Next trash any files in the startup folder (see location above) then place the following file in there (Applications / EndNote X5 / Cite While You Write / EndNote CWYW Word 20xx.bundle).
Start EndNote then Start Word.
NOTE: If this is Windows, then you’ll need to do the following instead:
1) Depending on the machine, you may need to open Word as an administrator to make the change. I will give the instructions for this. Otherwise step one is to open Word.
1. Go to the Start menu and type “winword.exe”, without the quotes into the search bar. Do not press enter.
2. Right click the winword.exe application that comes up in the search.
3. Choose Run As Administrator.
2) Go to the File menu at the top left of Word.
3) Choose Options.
4) Select Add-ins on the left hand side.
5) At the bottom of this page, next to Manage Com Add-ins, press Go.
6) Select the EndNote Cite While You Write item so it’s highlighted, then press Remove.
7) Next, you can add the EndNote X5 tools by doing the following:
1. Click the Add button on the right.
2. Navigate to “C:\Program Files\Common Files\ResearchSoft\Cwyw\15"
*Note that if you have common files installed in a different location, you would need to find this CWYW folder in that other location. If you are using a 64bit version of windows the path will be “C:\Program Files (x86)\Common Files\ResearchSoft\Cwyw\15”
3. Select EndNote CWYW.dll
4. Press OK.
5. Make sure EndNote Cite While You Write is now listed and checked.
7) Press OK.
8) Restart Word entirely.
Keep in mind this works to change between any version of EndNote’s Cite While You Write tools.