# Troubleshooting "Failed to communicate with RTA after 4 attempts" on the MiniSeq or NextSeq 500/550
Users may encounter the error "Failed to communicate with RTA after 4 attempts" during a sequencing run, which may cause the run to terminate prematurely. Occasionally, this may occur before the reagent cartridge is pierced, which would allow them to be reused for a new run setup.
**Troubleshooting steps**:
1. Ensure there is no antivirus software, firewall or proxy system blocking the connection between the Control Software and Real-Time Analysis (RTA\*).
\*RTA operates on port 8081
2. Confirm that Region Format in Windows is set to "English (United States)". Any other region may use different formats that are incompatible with our software. This can be done via Control Panel > Region > Formats tab > Format (dropdown menu).
3. Power Cycle the system. For power cycling instructions, review the article [How to Perform a NextSeq 500/550 Power Cycle.](https://knowledge.illumina.com/instrumentation/nextseq-500-550/instrumentation-nextseq-500-550-reference_material-list/000001972/?utm_source=agent\&utm_medium=email\&utm_campaign=kb)
If the issue persists, contact [Illumina Technical Support.](https://www.illumina.com/company/contact-us.html)
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| *For any feedback or questions regarding this article (Illumina Knowledge Article #9020), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000009020%20-%20Instrumentation%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |
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