TurboCAD, ViaCAD & SharkCAD: Common Issues

Activation says the license limit has been reached

This is the most common thing we hear from TurboCAD, ViaCAD, and SharkCAD customers, and it has a quick fix in almost every case.

A standalone (nodelock) license is tied to one computer at a time. If you’ve moved to a new PC, a new laptop, or reinstalled Windows, the old activation is often still “checked out” even after you’ve uninstalled the software there — uninstalling doesn’t automatically release the license back to our activation server.

What to do

• If the old machine still boots, open TurboCAD there first and deactivate/deregister the

license before installing on the new machine.

• If the old machine is gone, retired, or otherwise unreachable, contact support with your

serial number or order number and we can release the old activation from our side so you can activate on the new machine.

• If your product is several versions old and out of active maintenance and support, that’s

usually the moment to consider upgrading rather than fighting an old license — see the upgrade paths for TurboCAD Windows and DesignCAD.

If activation still won’t confirm with a good internet connection

Occasionally a Windows update corrupts the local license registry, and the program keeps asking to reactivate even though your license is valid and already active on our servers. Restart your computer completely (not just sleep/wake), reopen the software, and when prompted, re-enter the same license key you originally registered — this rewrites the local registry entry and normally clears it up without needing a new license.

TurboCAD won’t open, closes itself immediately, or shows a repair loop

If TurboCAD starts and then closes on its own, gets stuck in a “Please wait while Windows configures TurboCAD…” loop, or shows an SEHHandler crash message, work through these steps in order — most cases resolve at step 2 or 3 without needing to reinstall anything:

1. Restart Windows completely using Start → Power → Restart (not just a shutdown/power-on) — this clears any TurboCAD files or services Windows has locked mid-repair. 2. After restarting, go to Settings → Apps → Installed Apps, find your TurboCAD version, and run Modify → Repair. Let it finish fully, including any reboot it asks for. 3. Repair the Microsoft Visual C++ 2015–2022 Redistributables (both the x64 and x86 versions) the same way, then restart Windows again. 4. Right-click the TurboCAD shortcut and choose Run as administrator. 5. If it still won’t open, reset your user configuration: close TurboCAD, press Windows+R, go to %APPDATA%\IMSIDesign, and rename the TurboCAD folder for your version (for example “TurboCAD 2026” to “TurboCAD 2026_old”). TurboCAD rebuilds a fresh configuration on next launch. 6. Worth checking in parallel: Windows Security → Protection History, in case Windows has quarantined a TurboCAD file, and Windows Security → App & browser control → Smart App Control, which can interfere with legitimate installs when turned on.

Do not uninstall and reinstall as a first move — if the installer repair is already mid-cycle (the “configures TurboCAD” loop), reinstalling on top of it tends to make the loop worse rather than fixing it.

Learn the basics

New to TurboCAD, ViaCAD, or SharkCAD? These cover the fundamentals faster than trial and error: