You are using Microsoft Office 365 and think-cell is not available in PowerPoint [Excel].
The think-cell COM Add-In is not listed in the PowerPoint [Excel] Options:
This issue can happen, when think-cell was removed manually from the PowerPoint [Excel] Options in Office 365 using the
Manage: COM Add-Ins dialog.
To fix the issue, please perform a Microsoft Office 365 Online Repair:
Press Start or the Windows key → type
Control Panel → Enter.
Open Programs and Features.
Right click on your Microsoft Office installation:
Online Repair →
In case you still experience any further issues afterwards, please contact our support team