GoError: invalid character '<' looking for beginning of value

I have been having this error lately, have anyone saw it earlier? knows what it is?
the weird part is that the result gives me 100% in the checks, but not the total.

✓ Database OK…: 100.00% ✓ 9622 ✗ 0
✓ Status 200…: 100.00% ✓ 9622 ✗ 0
checks…: 8.42% ✓ 19244 ✗ 209138
data_received…: 100 MB 1.1 MB/s
data_sent…: 28 MB 309 kB/s
group_duration…: avg=35.63ms min=880.6µs med=3.26ms max=18.5s p(90)=29.06ms p(95)=155.37ms
http_req_blocked…: avg=2.28ms min=1µs med=2µs max=18.46s p(90)=3µs p(95)=4µs
http_req_connecting…: avg=1.59ms min=0s med=0s max=6.73s p(90)=0s p(95)=0s
http_req_duration…: avg=31.78ms min=782µs med=3.04ms max=5.76s p(90)=24.66ms p(95)=93.89ms
http_req_receiving…: avg=17.54µs min=4µs med=10µs max=9.92ms p(90)=28µs p(95)=37µs
http_req_sending…: avg=23.4µs min=4µs med=8µs max=30.5ms p(90)=16µs p(95)=24µs
http_req_tls_handshaking…: avg=675.96µs min=0s med=0s max=18.44s p(90)=0s p(95)=0s
http_req_waiting…: avg=31.74ms min=758µs med=3.01ms max=5.76s p(90)=24.53ms p(95)=93.79ms
http_reqs…: 218766 2430.727912/s
iteration_duration…: avg=35.66ms min=891.4µs med=3.28ms max=18.5s p(90)=29.15ms p(95)=155.79ms
iterations…: 218276 2425.28348/s
vus…: 999 min=1 max=999
vus_max…: 1000 min=1000 max=1000

You’re likely trying to incorrectly parse something as JSON. See this issue: Better error message for JSON decoding errors · Issue #773 · grafana/k6 · GitHub