Error Drawing Graphs with a fresh installation

Hello Guys,

i have an issue with a new installation of LibreNMS.
When i am looking at the Graphs of the servers i check, they only say “Error Drawing Graph”.
I absolutely don’t know how to solve this, and wasnt able to find any solution in this community too.

The output of the validate.php:

/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
====================================
Component | Version
--------- | -------
LibreNMS  | 1.68-41-ge7f2de79e
DB Schema | 2020_09_24_000500_create_cache_locks_table (176)
PHP       | 7.4.3
Python    | 3.8.5
MySQL     | 10.3.22-MariaDB-1ubuntu1
RRDTool   | 1.7.2
SNMP      | NET-SNMP 5.8
====================================

[OK]    Composer Version: 1.10.13
[OK]    Dependencies up-to-date.
[OK]    Database connection successful
[OK]    Database schema correct
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.
/etc/snmp/snmp.conf: line 5: Warning: Unknown token: default.

This is what the RRDTool says:

rrdtool graph /tmp/sZnKPYVtebM5pvLV  -g -l 0 -u 100 -E --start 1602490800 --end 1602577200 --width 1728 --height 484 -c BACK#EEEEEE00 -c SHADEA#EEEEEE00 -c SHADEB#EEEEEE00 -c CANVAS#FFFFFF00 -c GRID#a5a5a5 -c MGRID#FF9999 -c FRAME#5e5e5e -c ARROW#5e5e5e -R normal -c FONT#000000 --font LEGEND:8:DejaVuSansMono --font AXIS:7:DejaVuSansMono --font-render-mode normal COMMENT:'Load %                 Now       Min       Max     Avg\l' DEF:usage0=/opt/librenms/rrd/localhost/processor-hr-196608.rrd:usage:AVERAGE  DEF:usage0min=/opt/librenms/rrd/localhost/processor-hr-196608.rrd:usage:MIN  DEF:usage0max=/opt/librenms/rrd/localhost/processor-hr-196608.rrd:usage:MAX  CDEF:usage_cdef0=usage0,3,/ CDEF:usage_cdef0min=usage0min,3,/ CDEF:usage_cdef0max=usage0max,3,/ AREA:usage_cdef0#E43C00:'Intel Xeon Gold  ' GPRINT:usage0:LAST:%5.2lf%s GPRINT:usage0min:MIN:%5.2lf%s GPRINT:usage0max:MAX:%5.2lf%s GPRINT:usage0:AVERAGE:'%5.2lf%s\n' COMMENT:'\n' DEF:usage1=/opt/librenms/rrd/localhost/processor-hr-196609.rrd:usage:AVERAGE  DEF:usage1min=/opt/librenms/rrd/localhost/processor-hr-196609.rrd:usage:MIN  DEF:usage1max=/opt/librenms/rrd/localhost/processor-hr-196609.rrd:usage:MAX  CDEF:usage_cdef1=usage1,3,/ CDEF:usage_cdef1min=usage1min,3,/ CDEF:usage_cdef1max=usage1max,3,/ AREA:usage_cdef1#E74B00:'Intel Xeon Gold  ':STACK GPRINT:usage1:LAST:%5.2lf%s GPRINT:usage1min:MIN:%5.2lf%s GPRINT:usage1max:MAX:%5.2lf%s GPRINT:usage1:AVERAGE:'%5.2lf%s\n' COMMENT:'\n' DEF:usage2=/opt/librenms/rrd/localhost/processor-hr-196610.rrd:usage:AVERAGE  DEF:usage2min=/opt/librenms/rrd/localhost/processor-hr-196610.rrd:usage:MIN  DEF:usage2max=/opt/librenms/rrd/localhost/processor-hr-196610.rrd:usage:MAX  CDEF:usage_cdef2=usage2,3,/ CDEF:usage_cdef2min=usage2min,3,/ CDEF:usage_cdef2max=usage2max,3,/ AREA:usage_cdef2#EB5B00:'Intel Xeon Gold  ':STACK GPRINT:usage2:LAST:%5.2lf%s GPRINT:usage2min:MIN:%5.2lf%s GPRINT:usage2max:MAX:%5.2lf%s GPRINT:usage2:AVERAGE:'%5.2lf%s\n' COMMENT:'\n'
RRDTool Output

1809x523
OK u:0.06 s:0.01 r:0.06

I hope someone can help me with this problem!
If more information is needed, i will try to give them as soon as possible!