This article outlines the reason why you are getting this error, and provides a couple of ideas on a solution.
Google Sheets uses Google Apps Script to perform functions, such as moving data in to the sheet. When getting your data, the resulting data set is too large for the array limit of 52,428,800 bytes (50MB).
This is a set limitation by Google, and it cannot be "fixed" or affected in any way by Supermetrics. The only way to make your query work is to make it lighter.
How to make your query lighter?
1. Shorten the date range - get data only for the time you absolutely need it
2. Remove metrics you do not need - the more metrics you have, the more data is queried - remove unnecessary metrics
3. if the above are not an option, divide the query into two or more smaller queries, and then use Sheets functions to combine the results on a single sheet for reporting purposes
Combine new results with old-function
If none of the above for some reason suit your needs, you can try to solve the issue by using the Supermetrics function "Combine new data with old". It will pose some requirements for your query, such as having to include the dimension Date into the query, so it will not be an option if your query is not split by Date.