Landlord insurance

I recently purchased an investment property but I am unable to get house insurance on it.

The is a outstanding claim against my insurance from a tenant at another property for the last 2 and a half years.

This claim means that no insurer will quote me for insurance until the matter is resolved. My insurer at the other property will neither offer me insurance at the new property or settle the claim with the tenant.
Any advice great fully received

It doesnt mean no one will insure you. Have you spoke to a broker? Some insurers only ask whether you have had a claim at the property you are seeking to insure.