I'm trying to get CRISPRAnalyzeR working using your Docker container and test data and I'm running into an issue and would appreciate some help.
I will walk you through exactly what I did. I should mention I ran into the exact same issue using an ubuntu AWS instance as well as my local laptop (Windows 10).
1. I did a docker pull of the image: boutroslab/crispranalyzer:latest
2. I started the server as described in the docs:
C:\WINDOWS\system32>docker run --rm -p 8000:8000 boutroslab/crispranalyzer:latest
[CUSTOM] setting enhanced websocket settings
[CUSTOM] setting verbose shiny server and application logfiles
[CUSTOM] setting the path to the COSMIC database
[CUSTOM] EnrichR interface
[CUSTOM] setting the EnrichR URL
[CUSTOM] Set maximum upload Size
[CUSTOM] setting number of threads for Bowtie2
[CUSTOM] setting Logs
Starting Shiny-Server
3. I am able to open up CRISPRAnalyzeR in the browser

5. I upload pilotscreen.fasta as shown in the first screenshot.
6. I upload the 4 files (PBS-Replicate1.txt, PBS-Replicate2.txt, TRAIL-Replicate1.txt, and TRAIL-Replicate2.txt) simultaneously (by holding down CTRL to select all of them) as shown in the second screenshot.
7. I rename the samples so that there are only numbers and letters (also as shown in the second screenshot).
8. I hit the green Upload and Check Files button on the bottom.
9. I get a Disconnected from the Server message as shown in the third screenshot.
Should all of that have worked or am I missing something? Please let me know.