I just installed XOOPS and i get this error at the bottom of every page

Notice [PHP]: Only variables should be assigned by reference in file kernel/profile.php line 94
Notice [PHP]: Only variables should be assigned by reference in file include/common.php line 215
Notice [PHP]: Only variables should be assigned by reference in file kernel/config.php line 239
Notice [PHP]: Only variables should be assigned by reference in file kernel/config.php line 239
Notice [PHP]: Only variables should be assigned by reference in file kernel/groupperm.php line 229
Notice [PHP]: Only variables should be assigned by reference in file kernel/blockinstance.php line 169
Notice [PHP]: Only variable references should be returned by reference in file kernel/blockinstance.php line 111
Notice [PHP]: Only variables should be assigned by reference in file modules/system/blocks/system_blocks.php line 151
Notice [PHP]: Only variables should be assigned by reference in file kernel/groupperm.php line 229
Notice [PHP]: Only variables should be assigned by reference in file modules/system/blocks/system_blocks.php line 154
Notice [PHP]: Only variables should be assigned by reference in file modules/system/blocks/system_blocks.php line 159
Notice [PHP]: Only variables should be assigned by reference in file modules/system/blocks/system_blocks.php line 159


can anyone help me?

go into admin / got to preferences / general settings / disable php debug.