$MinPrecision::preccon
$MaxPrecision::preccon
$MaxPrecision cannot be less than $MinPrecision:
Block[{$MinPrecision = 30, $MaxPrecision = 20}, 2.`50 + 2.`50]This shows valid settings for $MaxPrecision and $MinPrecision:
Block[{$MinPrecision = 20, $MaxPrecision = 20}, 2.`50 + 2.`50]