Hi DeepakSharma,
According to your description, I have some questions.
- Does this issue occur with all .xlsb files?
- Is there any error message when Excel hangs?
- Where are the .xlsb files stored? Please copy them to other location to have a look.
- Have you installed recent updates for Excel? Here is the article about updates of volume licensed versions of Office, "Latest updates for versions of Office that use Windows Installer (MSI)"
I suggest you enter "excel /safe" in Run dialog, click OK to open Excel in safe mode, then open these .xlsb files to check if it works. Some startup settings will be ignored in safe mode.
If the issue persists, you could try to disable COM add-ins in Excel.
Go to File > Options > Add-ins > Manage COM add-ins > Go, clear all the boxes of any enabled COM add-ins, select OK.
Besides, it's best to back one of the .xlsb files, then change the extension name from .xlsb to .xlsm, then open this file to check this issue.
Any questions, please post back.