what is wrong

[xCoini]

every second:
    loop all players:
        if block below loop-player is diamond block:
            if loop-player's inventory contains 1 blaze powder:
                if loop-player's inventory contains 1 nether star named "&5- >&6 magisches Plasma&5 < -"
                if loop-player's level is higher or equal to 1:
                remove 1 blaze powder from the loop-player's inventory
                remove 1 nether star named "&5- >&6 magisches Plasma&5 < -" from the loop-player's inventory
                make console execute command "xp 1l %loop-player%"
                give loop-player 1 gold block named "&6Normaler Zauberstab1"
                stop

Error:
Empty configuration section! You might want to indent one or more of the subsequent lines to make them belong to this section or remove the colon at the end of the line if you don`t want this line to start a section (line 6)
"if loop-player's level" is not an entity type
(line 5)

 

[couger44]

every second:
    loop all players:
        if block below loop-player is diamond block:
            if loop-player's inventory contains 1 blaze powder:
                if loop-player's inventory contains 1 nether star named "&5- >&6 magisches Plasma&5 < -"
                if loop-player's level is higher or equal to 1:
                remove 1 blaze powder from the loop-player's inventory
                remove 1 nether star named "&5- >&6 magisches Plasma&5 < -" from the loop-player's inventory
                make console execute command "xp 1l %loop-player%"
                give loop-player 1 gold block named "&6Normaler Zauberstab1"
                stop

Error:
Empty configuration section! You might want to indent one or more of the subsequent lines to make them belong to this section or remove the colon at the end of the line if you don`t want this line to start a section (line 6)
"if loop-player's level" is not an entity type
(line 5)

I do not know if you noticed that detail. You put the ':' but you did not put more tabs later and followed the code on the same line.