This can happen due to multiple different reasons:

• There are read files in the current folder, but no sample is selected. In this case, please select one or more samples.
• There are no read files in the current folder. In this case, please navigate to a folder that contains NGS data in one of the required formats (i.e. fastq or fastq.gz) and select a sample (or multiple samples).
• Your license has expired. You can check the expiration date of your license on the Settings dashboard.