Preliminaries:

• Shopkeepers version: <Insert Shopkeepers version>
• Spigot version: <Insert output of /version command>

• I have checked that my issue/question does not get answered by:
  • The documentation.
  • The FAQ.
  • The Known Issues.
• I have checked all open and closed issues, but none seems to fit my issue/question.

Reproduction on a fresh and up-to-date Spigot server:

I was <able / not able> to reproduce my issue on a freshly set up and up-to-date Spigot server (currently <Insert output of /version command on up-to-date Spigot server>) with the latest version of Shopkeepers (currently <Insert latest tested Shopkeepers version>), with no other plugins and with no kinds of other server or client mods.

The issue:

Provide a detailed description of your problem and add as much information as possible which could help to reproduce the issue.

Include:

• Description of the issue.
• Step-by-step instructions on how to reproduce the issue.
• Observed behavior.
• Expected behavior.
• If items with special attributes are involved: Include instructions on how to create those items.
• Server logs (from server startup until issue). Consider enabling debug mode in the config for additional console output.
• If modified from default: Plugin configurations.
• ... Anything else that might be useful to reproduce and identify the issue.

shopkeepers version 2.16.5

I cannot help without further information. My current guess would be that the issue is caused by some incompatibility in combination with one of your other plugins.
Try to reproduce your issue on a fresh and up-to-date Spigot server and without other plugins. If it works there, then step by step add your other plugins until it breaks.

If you figure out which plugin is causing the issue, I can further investigate.