# Something went wrong?

The common problems and what to do. Back to the [README](../README.md#something-went-wrong). The full table of
error messages, with the older engine fixes, is in the [details](DETAILS.md#troubleshooting).

## While installing or starting

**My PC froze, or got very slow, the first time Strata started.**
That's normal while it starts, most of all the first time. Strata loads 35-55 GB into your RAM, locks part of it for
the graphics card, and works out how much of the model fits on your GPU. The mouse can freeze for a few minutes.
**Wait, and don't close the window.** The next starts are much faster. Still frozen after 10 minutes? Restart the
PC, close other programs (browsers use a lot of RAM) and try again. If it keeps happening, pick a smaller size (Q2_0
or IQ2_XS).

**It stopped while downloading or installing.**
Run `START-HERE.bat` (Linux: `./setup.sh`) again. It continues where it stopped.

**It says the NVIDIA driver is too old.**
Update it (NVIDIA App or [nvidia.com/drivers](https://www.nvidia.com/drivers)), restart the PC, and run
`START-HERE.bat` again.

**It says port 8080 is already in use.**
Strata is already running. Look for its window. Or another program uses the port: `START-HERE.bat --port 8081`.
Only an address that is really taken says "already in use". Any other reason (Windows keeps the port reserved, or
the config's `"host"` is not an address of this PC) is printed as what the OS said, with what to change (#769).

**"Windows blocked the Strata engine (or the image encoder) ... Smart App Control".**
On a clean Windows 11, Smart App Control refuses programs that are not signed, and Strata's `strata.exe` and
`strata-vision.exe` are not (#735). Turn it off (Windows Security > App & browser control > Smart App Control
settings; it cannot be turned back on without a reset of Windows), or, if only the image encoder is blocked, run
`START-HERE.bat --setup --vision no`.

**A new engine misbehaves after an update.**
An update keeps the engine it replaced in `engine\.previous` (one generation, about 210 MiB).
`python setup.py --rollback-engine` puts it back (and keeps the newer one there: run it again to go forward) (#670).

**Python or the build tools could not be installed.**
Install what it names (links are printed), then run it again. Everything already done is kept.

**Linux: the engine does not compile (`unsupported GNU version`, or `exception specification is incompatible` for
`cospi`/`sinpi`/`rsqrt`).** Two known mismatches between the CUDA toolkit and a new Linux (#601):
- gcc newer than 14 (Ubuntu 26.04's default 15): CUDA 12.x and 13.0 refuse it. Install g++-14 and run
  `CXX=g++-14 CUDAHOSTCXX=g++-14 ./setup.sh`.
- glibc 2.43 with CUDA 12.9: the toolkit's math headers clash with glibc's, already in CMake's first test compile.
  Use CUDA 12.8 or 13.x instead. Setup takes the newest toolkit it finds; `STRATA_NVCC=/usr/local/cuda-12.8/bin/nvcc
  ./setup.sh` makes it use that one (only that one).

**The first start takes minutes.**
It is reading 34-55 GB into RAM; the second start is faster while the files are in the OS cache. Started from Task
Scheduler, it can be 24x slower: see [Running it at startup](DETAILS.md#running-it-at-startup-task-scheduler).
On Linux the engine now asks the kernel to read the model files ahead (a cold start went from ~920 s to 70 s on one
PC); `STRATA_READ_AHEAD=0` turns that off. On Linux with transparent huge pages on `always`, the arena no longer asks
for `MADV_HUGEPAGE` on top (a fragmented machine spent minutes compacting memory, #771); `STRATA_NO_ARENA_THP=1` skips
that request on any setting.

## While it answers

**It's very slow and the disk light keeps blinking.**
Your PC is out of free RAM. Close other programs, or pick a smaller size (Q2_0 or IQ2_XS).

**An answer stopped with "the engine stopped unexpectedly".**
Usually not enough RAM (on Linux the system then stops the engine). Just send your message again: Strata starts the
engine by itself. If it keeps happening, close other programs or pick a smaller size.

**It says the prompt exceeds the context.**
The conversation is longer than the context you chose. Start a new chat, or run `SETUP.bat` and pick more
context.

**It is slower than the tables.**
The monitor plugged into the graphics card and other GPU programs take VRAM from the expert cache; RAM running below
its rated speed (enable EXPO/XMP in the BIOS) slows the CPU half.

**An earlier reply that came back empty is gone from the chat history (0.1.40, #843).**
The server leaves out finished assistant turns that have no text, so the next reply does not copy the empty ones.
`STRATA_KEEP_EMPTY_TURNS=1` in the server's environment renders them as before.

**A Turing card (RTX 20) reads prompts above ~90K tokens differently (0.1.40, #743).**
The prompt's top-k selection takes a wider kernel there, with the same ids. `STRATA_TOPK_STREAM=0` restores the old one.

**Pictures are refused, or slow.**
"this server was started without the vision encoder": the model was set up for text only - run setup again with
`--vision gpu` (or `--vision cpu`). Pictures that take several seconds (about 3 s at 300 image tokens on 8 cores, more with more tokens) are read by the encoder on the CPU; `--vision gpu`
(NVIDIA, ~1.4 GB of VRAM) makes it 0.1-0.5 s.

## AMD cards

**"No AMD GPU found (the amdgpu driver's KFD topology is empty)" on Linux.**
The kernel's amdgpu driver is not loaded for the card. Integrated Radeon GPUs are listed as not supported; setup
lists every card it found and whether Strata can use it.

**The engine stops at start with the card's name, its architecture and the build's list.**
The engine was compiled for another card (for example after moving the Strata folder to another PC). Run
`./setup.sh --setup --backend hip`: it compiles the engine for this card's architecture.

**Large pinned host allocations fail on ROCm although RAM is free.**
See [AMD_HIP.md](AMD_HIP.md#model-and-serving-configuration): the mapped expert mode avoids the full pinned arena.

## Still stuck?

Look in the [full troubleshooting table](DETAILS.md#troubleshooting), or open an
[issue](https://github.com/Niko1221/Strata/issues) and attach `strata-<model>.log` from the Strata folder.