Hi Markéta,
The limit you’re hitting relates to the maximum cardinality of a dimension containing metrics.
The maximum size of a non-metric dimension is set to 100,000, as explained in GD Cloud’s
Limits. However, for dimensions with metrics, the limit is 1000. In most cases, this is the limit for the number of Columns in a visualization (which is where Metrics are displayed by default); but when you Pivot a table to change where the Metrics are displayed, it can also apply to the number of rows instead. It’s important to keep that in mind when building the visualizations so that they don’t exceed that limitation: