Setting up a NAS as a Plex server is one of the best things about owning one — you get to build your own Netflix-style library with minimal effort. Plex automatically sorts and labels your media, giving you a sleek, organized collection instead of scattered Blu-ray discs or endless nested folders, in case you’ve already gone digital. But when Plex doesn’t run smoothly just when you’ve gotten comfortable on the couch to watch something, it can kill the vibe in an instant. So, here are some common Plex issues and how you can fix them before they ruin your movie night.

8 All buffering and stuttering — and no playback

We’ve all been there, right?

One lazy weekend afternoon, you settle in to binge your favorite show, and instead of smooth streaming, you’re stuck watching the buffering wheel spin — all it's doing is testing your patience. This usually happens due to network congestion, slow server performance, or insufficient transcoding capacity.

To fix it, make sure your NAS has enough processing power to handle Plex. If you're streaming remotely, you can lower the streaming quality to match your internet speed. For local playback, use Direct Play instead of transcoding, and if possible, switch to a wired connection instead of Wi-Fi. Also, enabling hardware-accelerated transcoding in Plex settings can significantly improve performance.

7 High CPU usage due to transcoding

You've got a problem if the CPU is constantly at 100%

If your Plex server is sluggish, and you notice that CPU usage is constantly maxing out in the control panel, transcoding is likely the culprit. Plex converts media formats on the fly when the format isn’t supported by the client device, which can put a huge strain on your processor.

To fix this, enable hardware-accelerated transcoding in Plex settings — some of the best NAS models built for Plex support the feature. Converting high bitrate files into a more efficient format like H.265 beforehand can also reduce the workload. Ideally, you should store your media in common formats that don’t require transcoding in the first place.

6 Slow library scanning and metadata issues

Missing media? Incorrect titles? There’s a solution

You put together a Plex server primarily for a well-organized media library, so when it's not organized, you have a potentially big problem to fix. This issue usually happens due to improper file naming, large media collections that take forever to index, or slow storage speeds.

To speed things up, follow Plex’s recommended naming conventions — a simple format with film or TV show name with the correct release year and episode sequence should do the trick. If your NAS has an SSD bay, storing metadata and database files on an SSD instead of spinning hard drives can improve scan times. If the metadata is still wrong, manually refresh the library and consider using third-party metadata tools to fix any discrepancies.

5 Remote Plex streaming not working

What’s the point of your own Netflix without remote streaming?

Having your own Netflix alternative gives you the perk of watching your content from anywhere in the world — though sometimes, remote streaming fails to work reliably. In most cases, incorrect port forwarding rules and ISP restrictions are to blame.

First, ensure Remote Access is enabled in Plex settings to confirm you haven’t overlooked this basic setting. If it’s still not working, manually forward port 32400 on your router to allow external connections. In case your ISP blocks certain ports or uses CGNAT, remote access may not work reliably. In that case, using a VPN or a cloud-based relay service can help.

When accessing your NAS remotely, always set up port forwarding properly and double-check everything to avoid exposing your system to external security risks.

4 You’ve run out of storage

Media hoarders, this one's for you

Many of us find it hard to let go of that 30-season sitcom that is still our favorite meal-time watch, even though it’s eating up half of our NAS storage. While deleting such large media collections might be necessary as a last resort, there are a few workarounds that you can try first.

To free up space, convert large 4K files to H.265, which retains the quality but at a much smaller file size. Enable Plex’s automatic deletion for viewed content and clear temporary files created during transcoding to open up more space — remember, every single MB counts when you’re running out of space. If you can’t bring yourself to delete anything, offloading old content to external storage might be an option.

3 Audio not working or codec not supported

No, nothing’s wrong with your ears, it’s just the audio acting up

Broken or no audio when you play something often occurs due to unsupported codecs or incorrect audio settings.

If Plex says an audio codec isn’t supported, try enabling automatic audio transcoding in settings to fix the incompatibility issue. For surround sound setups, make sure your playback device supports DTS, Dolby Digital, or other relevant formats, and ensure the setting matches both your server and the client device (like your TV). Some older TV sets may not support anything newer than stereo sound. Finally, if you experience audio delay, using an external media player like VLC or Kodi can sometimes fix the issue.

2 Plex server crashing or becoming unresponsive

Random Plex crashes are a bigger mood killer than caramel popcorn

Most of these crashes can be attributed to memory bottlenecks, high CPU usage, or outdated software. To overcome these issues, ensure your Plex server is updated to the latest version. If it still crashes, check CPU and RAM usage — closing unnecessary background tasks may help in the short term, with hardware upgrades being a better, long-term solution.

Consider running Plex on a dedicated NAS instead of a computer that is also performing its regular PC duties, which can improve stability. If your library is large, clearing the cache and rebuilding the database can resolve issues caused by corrupted files. And if everything fails, you can reinstall Plex to give your server the fresh start it has long needed.

1 Subtitles not displaying or out of sync

"But that’s not what the character just said..."

Watching your favorite high-emotion Korean drama without subtitles could leave you frustrated or with hilariously delayed emotions — it could go either way! While the issue can result from incorrect subtitle encoding, timing mismatches, or unsupported formats, there are a few easy fixes.

Try using an external subtitle file in SRT format, which is widely supported. If subtitles are still out of sync, most Plex players allow you to manually adjust the timing during playback to get a precise sync. Using media files with burned-in subtitles (where they’re embedded in the video) can also prevent compatibility issues from the get-go.

Building the ultimate Plex media server

One of the biggest reasons people invest in a NAS is to organize and stream their media collection through Plex. While most NAS models support Plex natively, you don’t have to buy a pre-built system just for it. If you’re a DIY kind of person, you can build your own NAS from scratch or even repurpose an old PC into a powerful Plex server that is perfect for your home.