0% Error: Server error: (500) Internal Server Error Internal error: There was an internal error

[Amatcov]

When trying to get over 500 000 rows/day the error message pops-up:
0% Error: Server error: (500) Internal Server Error Internal error: There was an internal error

In the code, max.results = NULL

To solve the issue, I set max.results = 500 000 (per day) and it works
Although I have almost 1 000 000 rows / fetch.by = "week"

The message I get if 500 000 rows are downloaded is:

**_Warning messages:
1: Only 500000 observations out of 1000000 were obtained. Set max.results = NULL (default value) to get all results.
2: 1 failed to parse.
3: Data contains sampled data. Used 473168 sessions (86% of sessions).

toc()
524.15 sec elapsed_**

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Question: is the any other more effective way to be able to download all 1 000 000 rows instead of just 500 000?