| Issue | Likely Cause | Solution | |-------|--------------|----------| | Installer fails to start | Corrupted download or missing VC++ runtime | Re-download; install Microsoft Visual C++ Redistributable (All-in-one) | | "License not found" error | Activation server offline or firewall blocking | Check internet; add Tukacad to firewall exceptions | | Crashes when hatching | Graphics driver conflict | Update GPU drivers; disable hardware acceleration in Tukacad settings |