The fastest way to remove the above error is to remove IES data from the file.
Following steps requires to remove IES data from file.
1. Go to Setting tab > Rendering > Light Manager.
2. Select all BBES lighting symbols, Toggle off Properties and IES data option. (See below image)
3. Wait till process completes.
4. Restart the AECOsim Building Designer.
This should resolve your IES files problem.