InvalidPluginAssemblyContent error when importing a solution in Microsoft Dynamics 365

This article provides a resolution for the issue that you may receive the InvalidPluginAssemblyContent error when importing a solution in Microsoft Dynamics 365.

Applies to:   Microsoft Dynamics 365 Customer Engagement Online
Original KB number:   4500635

Symptoms

When attempting to import a solution in Microsoft Dynamics 365, the solution import fails with the following error:

Plug-in assembly does not contain the required types or assembly content cannot be updated.

Error code: 8004418b

Cause

This error occurs if you have modified an assembly included in this solution but the version of the solution was not incremented.

Examples:

Changing the name, version, isolation level, public key token, or culture of the assembly without increasing the version of the solution will cause this error. Changes like these require a solution upgrade (version change) instead of a solution update.

Resolution

Increase the version of the solution and try the import again.

More information

For more information, see the following articles:

• Update a custom workflow activity using assembly versioning
• Release a new version of your managed solution