# Recovering from HTTP error \[500 Internal Server Error\], attempt 1 of 500 Retrying in 120 seconds

**URL:** <https://forum.ecmwf.int/t/recovering-from-http-error-500-internal-server-error-attempt-1-of-500-retrying-in-120-seconds/13940>\
**Category:** API\
**Tags:** api, cds\
**Created:** [4 August 2025 23:16 UTC](https://forum.ecmwf.int/t/recovering-from-http-error-500-internal-server-error-attempt-1-of-500-retrying-in-120-seconds/13940 "2025-08-04T23:16:54Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Luis\_Lazcano](https://forum.ecmwf.int/letter_avatar_proxy/v4/letter/l/7feea3/32.png) [@Luis\_Lazcano](https://forum.ecmwf.int/u/Luis_Lazcano)\
**Post date:** [4 August 2025 23:16 UTC](https://forum.ecmwf.int/t/recovering-from-http-error-500-internal-server-error-attempt-1-of-500-retrying-in-120-seconds/13940/1 "2025-08-04T23:16:55Z")

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I am currently trying to download specific humidity and vertical velocity through the next code:

**import cdsapi**

**fecha = “2022”,“2023”,“2024”**

**nivel = “200”,“500”,“600”,“700”,“850”,“925”,“1000”**

**meses = “1”, “2”, “3”, “4”, “5”, “6”, “7”, “8”,“9”,“10”,“11”,“12”**

**for j in range(len(nivel)):  
for i in range(len(fecha)):  
for k in range(len(meses)):  
dataset = “reanalysis-era5-pressure-levels”  
request = {  
“product\_type”: [“reanalysis”],  
“variable”: [  
“specific\_humidity”,  
“vertical\_velocity”  
],  
“year”: fecha[i],  
“month”: [  
meses[k]  
],  
“day”: [  
“01”, “02”, “03”,  
“04”, “05”, “06”,  
“07”, “08”, “09”,  
“10”, “11”, “12”,  
“13”, “14”, “15”,  
“16”, “17”, “18”,  
“19”, “20”, “21”,  
“22”, “23”, “24”,  
“25”, “26”, “27”,  
“28”, “29”, “30”,  
“31”,  
],  
“time”: [  
“00:00”, “01:00”, “02:00”,  
“03:00”, “04:00”, “05:00”,  
“06:00”, “07:00”, “08:00”,  
“09:00”, “10:00”, “11:00”,  
“12:00”, “13:00”, “14:00”,  
“15:00”, “16:00”, “17:00”,  
“18:00”, “19:00”, “20:00”,  
“21:00”, “22:00”, “23:00”,  
],  
“area”: [  
50, -180, -50,  
180,  
],  
“grid”: [  
2.0, 2.0,  
],  
“pressure\_level”: [nivel],  
“data\_format”: “netcdf”,  
“download\_format”: “unarchived”  
}  
client = cdsapi.Client()  
target = “shum\_vvel”+ str(nivel)+“mb\_”+str(fecha[i])+“\_” + str(meses[k])+“.nc”  
client.retrieve(dataset, request,target).download()**

However, I never achieved to download the files. Is there an error in my code that causes the error?

Help me please, it is been very frustrating during the last two months

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<div class="post-metadata">

**Author:** ![Pei\_Zilan](https://forum.ecmwf.int/letter_avatar_proxy/v4/letter/p/db5fbb/32.png) [@Pei\_Zilan](https://forum.ecmwf.int/u/Pei_Zilan)\
**Post date:** [1 October 2025 10:18 UTC](https://forum.ecmwf.int/t/recovering-from-http-error-500-internal-server-error-attempt-1-of-500-retrying-in-120-seconds/13940/2 "2025-10-01T10:18:51Z")

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hi I am facing the same question. but the most strange thing is, when I change my wifi, this problem solved…it still puzzle me, do you have any idea about it?