Hotspot Error Messages
Updated 14 Oct 2026. The 36 messages a Pi-Star user is most likely to see in the logs, what each one means, and what to try first. Every message was checked word for word against the programs running on a real Pi-Star hotspot. The meanings come from each program's own source code, and the remedies are the usual first things to try. %s, %u and %d are filled in with a name or number when the message prints.
New to hotspots? Inside a Hotspot explains what each part and program does.
MMDVMHost (the main program that talks to the modem board)
What it is: MMDVMHost is the core program on a Pi-Star hotspot. It talks to the modem board (the radio part of the hotspot), decodes what your radio sends, and passes it to the right gateway program for each mode.
| Message | Plain meaning | Suggested remedy |
| Unable to read the firmware version after six attempts | The software cannot talk to the modem board at all. Wrong modem type picked in setup, board not seated, or bad firmware. | Check the modem type in Configuration matches your board (running sudo pistar-findmodem can help). Power off, reseat the board, power on. If it still fails, reflash the board firmware. |
| No reply from the modem for some time, resetting it | The board stopped sending its regular status replies, so MMDVMHost closes the connection and opens it again. | Check the board is seated firmly and the power supply is good. If it keeps happening, update the board firmware. |
| Cannot open device - %s | A port could not be opened: either the modem's serial port or the OLED display's port. Usually the wrong modem or display type in setup. | Pi-Star picks the port from the modem type, so check the modem type and display type in Configuration. Reboot so nothing else is holding the port. |
| The MMDVM is not responding to the SET_FREQ command | The board did not answer the frequency command at all. This usually points to a firmware problem. | Update the board firmware so it matches Pi-Star, then reboot. |
| Received a NAK to the SET_FREQ command from the modem | The board refused the frequency because it is outside what the board can do. | Set a frequency inside the band your board supports (for example 430 to 450 MHz on a UHF board). |
| Received a NAK to the SET_CONFIG command from the modem | The board refused the settings it was sent. | Recheck the modem type and settings in Configuration, save, and reboot. Update the board firmware if it is old. |
| MMDVM protocol version: %u, unsupported by this version of the MMDVM Host | The modem firmware and the Pi-Star software are too far apart in age. | Update Pi-Star from the Admin page, then update the board firmware (sudo pistar-modemupgrade, or Expert, Modem FW Upgrade). |
| DMR enabled in the host but not in the modem firmware, disabling | DMR is turned on in setup but the board firmware does not have it. The same message exists for every mode. | Turn that mode off in Configuration, or flash firmware that includes it. |
| MMDVM TX buffer has overflowed | Data arrived from the Pi faster than the board could transmit it, usually a burst after a delay on the network. | Harmless if it happens now and then. If it happens often, check your internet connection for dropouts or delays. |
| MMDVM RX buffer has overflowed | The board's own processor could not keep up with what it was receiving. | Usually a one-off and harmless. If it happens often, update the board firmware. |
| MMDVM ADC levels have overflowed | Repeater boards only: the receive audio coming into the board from the radio is too strong. Hotspot boards never report this. | Reduce the audio level going from the radio into the board. |
| MMDVM DAC levels have overflowed | Repeater boards only: the transmit level is set too high. Hotspot boards never report this. | Lower TXLevel in Configuration, Expert, MMDVMHost. |
| Unable to resolve the address of the DMR Network | MMDVMHost cannot look up its DMR network address. On Pi-Star that is normally DMRGateway on the same Pi, so the cause is usually a wrong setting rather than the internet. | Save Configuration again to rewrite the settings. If it repeats, check the Address under DMR Network in Expert, MMDVMHost. |
| DMR, socket error when writing to the DMR Network | MMDVMHost could not send data on to the DMR network side. | Check the local network. Reboot the router and the hotspot. |
| Cannot open ID lookup file - %s | The DMR ID list file is missing, so callsigns will not show. | Run Update on the Admin page to download the ID list again. |
| ID lookup file has no entry - %s | The ID list file is there but empty, often after a failed download. | Run Update on the Admin page to download the ID list again. |
| Cannot bind the UDP address, err: %d | A network port is already in use: a second copy of a program is running, or two programs are set to the same port. | Reboot the hotspot. If it repeats, check that no two programs are set to the same port. |
| I2C: Failed to acquire bus access/talk to slave 0x%02X | The small OLED display is not answering. | Set the correct display type and port in Configuration, or set the display to None if you have no display. |
DMRGateway (links the hotspot to BrandMeister, TGIF, XLX and others)
What it is: DMRGateway sits between MMDVMHost and the DMR networks. It logs in to BrandMeister, TGIF, DMR+, XLX and others, and lets one hotspot use more than one DMR network at the same time.
| Message | Plain meaning | Suggested remedy |
| %s, Login to the master has failed, retrying login ... | The DMR server turned down the login. Almost always a wrong hotspot password, sometimes a wrong DMR ID. It can also appear when the server drops a link that was already connected. | Check the hotspot password in Pi-Star matches the one set in your BrandMeister SelfCare page exactly (it is case sensitive). Check your DMR ID. |
| %s, Login to the master has failed, retrying network ... | Same, at a later step in the login. | Same as above: check the hotspot password and DMR ID. |
| %s, Connection to the master has timed out, retrying connection | The DMR server stopped answering. An internet dropout or the server is down. | Check the internet connection. Try another server from the list. Check the network's status page. |
| %s, Could not lookup the address of the master | The server name cannot be looked up: a DNS problem or a bad server name. | Pick the server again from the list in Configuration. Check internet and DNS. |
| %s, Master is closing down | The server told the hotspot it is going offline. | Wait, or pick another server. Nothing to fix on your end. |
| %s, Socket has failed, retrying connection to the master | The network connection to the server broke. | Check the internet connection. Reboot the router and the hotspot. |
| Could not lookup the address of the MMDVM Host | DMRGateway cannot find MMDVMHost on the same Pi. A setup problem. | Reboot the hotspot. If it repeats, save Configuration again to rewrite the settings. |
| XLX%s, Unexpected data from slot %u %s%u | XLX traffic arrived on a timeslot or talkgroup that the XLX settings do not match, so it was dropped. | Check the XLX slot and talkgroup settings in Configuration. |
YSFGateway (Fusion)
What it is: YSFGateway connects the hotspot to Yaesu System Fusion (C4FM) reflectors, both YSF and FCS. It keeps the reflector list and handles linking and unlinking.
| Message | Plain meaning | Suggested remedy |
| Link has failed, polls lost | The YSF reflector stopped answering, so the link dropped. | Link again, or try a different reflector. |
| Invalid YSF reflector id/name - "%s" | The reflector asked for is not in the hosts list. | Pick the reflector again from the list. Run Update on the Admin page to refresh the hosts list. |
| Unknown FCS reflector - %s | Same, for an FCS reflector. | Pick the reflector again from the list. Run Update on the Admin page. |
| YSFGateway: cannot find the address of the MMDVM Host | YSFGateway cannot find MMDVMHost on the same Pi. | Reboot the hotspot. If it repeats, save Configuration again. |
| Unable to resolve the address of the YSF network | An internet or DNS problem. | Check the internet connection. Reboot the router and the hotspot. |
P25Gateway
What it is: P25Gateway connects the hotspot to P25 reflectors. Each reflector is a talkgroup number, and the gateway links to it when you key up on that talkgroup.
| Message | Plain meaning | Suggested remedy |
| Cannot open the Id lookup file - %s | The P25 ID list is missing, so callsigns will not show. | Run Update on the Admin page to download the list again. |
| P25 Talkgroups can only be 16 bits. %u is too large | An entry in the P25 hosts list has a talkgroup number above 65535, so it was skipped while the list loaded. You did not key it. | Harmless. If you added your own entries to the hosts list, check their numbers. |
NXDNGateway
What it is: NXDNGateway connects the hotspot to NXDN reflectors. Like P25, each reflector is a talkgroup number, linked when you key up on it.
| Message | Plain meaning | Suggested remedy |
| Cannot open the NXDN Id lookup file - %s | The NXDN ID list is missing, so callsigns will not show. | Run Update on the Admin page to download the list again. |
M17Gateway
What it is: M17Gateway connects the hotspot to M17 reflectors. It handles linking to a reflector and module.
| Message | Plain meaning | Suggested remedy |
| Unable to resolve the address of %s | The M17 reflector name cannot be looked up. | Check the reflector name is spelled right. Check internet and DNS. |
| Timeout in state %d | A rare timeout in the gateway's linking steps. A normal failed link shows a different message. | Usually harmless. Try linking again. |
ircDDBGateway (D-STAR)
What it is: ircDDBGateway connects the hotspot to D-STAR reflectors (REF, XRF, DCS and XLX) and to the ircDDB network, which routes callsign calls and shows who is heard. It handles linking, unlinking and D-STAR callsign routing.
ircDDBGateway does not write plain-English error messages the way the other programs do, so there is no list for it here.
A noncommercial hobby reference compiled by N6JET, gathered from public sources and shared freely for anyone interested in amateur digital voice.