dbForge SQL Complete shouldn't cause such issue.
Could you please send us the screenshot of this to supportATdevartDOTcom for investigation.
Also, please perform the following:
1. Close SSMS.
2. Uninstall dbForge SQL Complete with all options being selected on the 'Uninstall options' page of the Uninstall wizard.
3. Run SSMS and check whether the fonts were reset back to normal. If so, please perform the steps 4-6 below.
4. Close SSMS.
5. Install dbForge SQL Complete once again.
6. Run SSMS and check the fonts once again.
Please also provide us all the information from the 'About Microsoft SQL Server Management Studio' window by selecting 'Help -> About' from the main menu and then clicking the 'Copy Info' button.
Also, please be aware that SSMS fonts can be reset in the 'Environment -> Fonts and Colors' branch of the 'Options' window that can be invoked be selecting 'Tools -> Options' from the main menu.
Please also check that you have installed the latest build 4.0.65 of dbForge SQL Complete:
http://www.devart.com/dbforge/sql/sqlco ... nload.html