3DEXPERIENCE SOLIDWORKS R2026x FD01 Update Error – Version Mismatch

After the 3DEXPERIENCE Platform was upgraded to R2026x FD01 on Saturday, February 7th, 2026, some users are encountering a warning that states “There is a version mismatch between SOLIDWORKS and the language resources for <installed language>. Use the Installation Manager or go to the customer portal to download and install the required language files for 2026 SP1.0.”

After encountering this error, SOLIDWORKS Design does not load, and the user is unable to use the software.

BR10000419611 in the DS Knowledge Base describes this error and 2 possible solutions to resolve it:

Solution 1: Use an administrative Command Prompt to run a command from DS Support

1. Locate Command Prompt in the Start menu
2. Either right click and choose “Run as administrator” or choose “Run as administrator” on the right column
   
3. In the Administrative Command Prompt, type the following, including the double quotes surrounding the file-path:
   • “C:\Program Files\Dassault Systemes\SOLIDWORKS 3DEXPERIENCE R2026x\win_b64\resources\MSI\SolidWorksR428FD01PP2\hotfix.exe” /reinstall /s /k
     
4. Wait until the command is finished processing (you will be warned NOT to end the Command Prompt window while this is happening). You should see a message about a Hotfix being removed and then reinstalled.
5. Once complete, you can close the Command Prompt.
6. Reboot your machine. May not be necessary, but if this doesn’t work the first time, repeat steps 1-5 and then reboot.
7. Launch SOLIDWORKS again and test the behavior.

Solution 2: Uninstall Dassault Systemes SOLIDWORKS 3DEXPERIENCE R2026x, then reinstall SOLIDWORKS Design

These steps only need to be followed if Solution 1 above does not resolve the issue

1. To uninstall, follow the method 3: Unable to connect to 3DExperience after platform upgrade

Click Here

1. To reinstall, follow: How To Install SOLIDWORKS Connected (3DEXPERIENCE SOLIDWORKS)

Click Here

1. Once complete, attempt launching SOLIDWORKS again.