eBay has specific API limits for selling and syncing inventory. Some of the API calls for specific processes are limited to 25,000 requests per day and some are higher. This is not related to Hyperspace, but related to your specific eBay account.
So your specific eBay account has exceeded its own usage limits.
If you have received this error, you can remedy the issue by filling out an App Check form in your eBay developer account. To access your eBay developer account click here: eBay Developer Account.

Once you have logged in, click here (App Check) to see the App Check tab. It will appear on the far right.

Please fill out the form with the following details:
Application Title / Summary: Hyperspace
Application Details: Product and Inventory Feed
Products * Order API, Inventory API
Purpose of request* Increase my call limit
Programming Language* PHP
Compatibility Level* 983
Format* ALL
Application ID* (This is based on your App ID)
Application URL* https://hyperspacecloud.com
eBay Logo Used On The Application* Yes https://hyperspacecloud.com/assets/images/ebay_logo.png
Number of Simultaneous Threads* 5
Password Collection* No
Auth & Auth* OAUTH
Message Field* Save in our database and show in our app to resolve the issue
Denial of Service* This is an user interaction web based application. It is required to login in order to use the application.
XSS Attacks* This is an user interaction web based application. It is required to login in order to use the application.
SQL Attacks* We used MongoDB with hashed password
CSRF Attacks* NA
System Errors* Save in our database and show in our app to resolve the issue. Retry in the next time if items are updated.
Application Errors* Save in our database and show in our app to resolve the issue. Retry in the next time if items are updated.
Call Volume Estimate*
Call Name.......Hourly Volume.....Daily Volume
AddFixedPriceItem.............5000...................5000
ReviseFixedPriceItem..........30000....................720000
RelistFixedPriceItem..........30000....................720000
ReviseInventoryStatus..........30000....................720000
Declaration*
I have read and understood the certification requirements and Policies (initials)
You may need to wait a day or two for eBay to approve your account for higher usage limits.