Metamask wallet connection problems may happen on any dApp. This can happen when another wallet extension is preventing the Metamask wallet to connect (TrustWallet, Coinbase, or Safepal, for example).
On Zenland, this issue can happen while launching the escrow and marketplace dApp (login page), or claiming ZENF Presale tokens (token page).
To fix it:
Step 1. Switch off (or uninstall) other wallets before connecting Metamask;
For it, right-click on the wallet extension, Coinbase for example), choose “Manage extension”, and switch the wallet off.
From the notification appearing on the Metamask connection request, it is clear that the wallet itself is suggesting switching off other wallets in order to exclude connection barriers.
Step 2. Refresh the page and try connecting again.