Layers that have objects assigned to them cannot be removed until those objects are reassigned to a different layer or are deleted. Layers 0 and DEFPOINTS and the current layer cannot be removed.
The selected layer is removed.
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator at webmaster@entercad.forsenergy.ru to inform them of the time this error occurred, and the actions you performed just before this error.
More information about this error may be available in the server error log.
Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.