This is an operating system error and can indicate different error conditions.
These errors are not specifically documented in the ArcGIS Pro Help system.
In some cases, this error may include other messages that can help you to understand the problem or find additional information.
If the error message includes Something unexpected caused the tool to fail, consider contacting Esri Technical Support to Report A Bug. If any additional messages are included, sites such as Microsoft's Support and Help website may be helpful.