Because version 1.8 is no longer updated, you may encounter some problems. Here are solutions:
MegaDownloader 1.8 is a popular third-party desktop client designed to manage and accelerate downloads from the MEGA cloud storage platform
Unlike the MEGA Sync Client, you can download public links without signing into a MEGA account. For private links requiring a decryption key (the key after # in the URL), you just paste the full link.
: Click the "+" button or "Open Links" menu to paste your MEGA URLs. Start Download