Error message

• Deprecated function: abs(): Passing null to parameter #1 ($num) of type int|float is deprecated in format_size() (line 138 of core/includes/common.inc).
• Deprecated function: abs(): Passing null to parameter #1 ($num) of type int|float is deprecated in format_size() (line 138 of core/includes/common.inc).
• Deprecated function: abs(): Passing null to parameter #1 ($num) of type int|float is deprecated in format_size() (line 138 of core/includes/common.inc).