Handling your concern would depend if you mean importing Fixed assets accounts in the Chart of Accounts or Fixed assets themselves in QuickBooks Online (QBO) Advance, Vinothini.
To proceed, may I ask for the specific error code when you import your fixed assets to QBO? Also, can you confirm if you import to Fixed assets accounts in the Chart of Accounts or Fixed assets itself? This information will help me assist you more effectively and efficiently.
In the meantime, I recommend clearing the cache and cookies of your browser to remove excessive data build-up that impacts the platform's performance. You can also use a different QuickBooks-supported browser and ensure that your current browser is both supported and updated to the latest version.
After clearing your browser's cache or data, please re-import your fixed assets again using the steps in the resources below if you mean either of the two questions above:
Once everything is perfectly fine, you can also check out this article to learn how to customize a report in QBO: Save a customized report in QBO.
Feel free to reply back on this thread if you mean something else.