| Online Activation | Offline Activation | |-------------------|--------------------| | Click the link directly in the software. | Copy the link to a USB drive, open it on an internet-connected PC, download an .auth file. | | Instant, no files to manage. | Requires moving files between computers. | | Link expires after first use. | The .auth file is single-use but can be generated multiple times from the same link (if allowed by license). |
Temporarily disable any VPN or proxy. Add mitcalc.com and license.mitcalc.com to your antivirus/firewall whitelist. Use port 443 (HTTPS) – MITCALC does not use custom ports. Error 4: Link expires immediately (time-limited demo licenses) Cause: Some evaluation licenses are valid for only 7 or 30 days, and the link auto-expires after the first use. mitcalc authorization code link
Purchase a full license. There is no way to extend a time-limited link. Error 5: No link received after purchase Cause: Payment gateway delay, wrong email address, or the reseller failed to forward the license. | Requires moving files between computers
| Purpose | Description | |---------|-------------| | | Validates that you are a legitimate licensee. | | Hardware binding | Locks the license to your machine ID (hard disk serial, MAC address, etc.). | | Prevents sharing | Stops a single license from being used on dozens of computers. | | Enables updates | Allows you to reauthorize after major Windows updates or hardware changes. | | Temporarily disable any VPN or proxy
Copy the entire link. Paste it into Notepad first to check for hidden characters. Then copy from Notepad into the activation window. Error 3: "Connection to activation server failed" Cause: Your firewall, proxy, or antivirus is blocking MITCALC.
You need to deactivate the license on the old machine first. Go to C:\Program Files\MITCALC\ and look for a tool called DeactivateLicense.exe . Run it, then use the same link again on the new machine. If that fails, contact MITCALC support with your order number. Error 2: "Invalid link format" Cause: You may have copied only part of the URL, or extra spaces/line breaks were included.