What it means
The gas limit set on the transaction is below the minimum the network requires just to accept it, before any contract logic runs. Every transaction has a base cost (21,000 gas for a simple transfer, more when data is attached), and this limit did not cover it.
How to fix it
Raise the gas limit and resubmit. Wallets estimate the limit automatically, so this error almost always means a manual gas limit was set too low. Clear the custom value and let the wallet estimate.