<p>I am executing the below-mentioned command to install Prometheus.</p>
<pre><code>helm install my-kube-prometheus-stack prometheus-community/kube-prometheus-stack
</code></pre>
<p>I am getting the below error message. Please advise.</p>
<pre><code>Error: unable to build kubernetes objects from release manifest: error validating &quot;&quot;: error validating data: [ValidationError(Alertmanager.spec): unknown field &quot;alertmanagerConfigNamespaceSelector&quot; in com.coreos.monitoring.v1.Alertmanager.spec, ValidationError(Alertmanager.spec): unknown field &quot;alertmanagerConfigSelector&quot; in com.coreos.monitoring.v1.Alertmanager.spec]
</code></pre>

<p>Hello @saerma and welcome to Stack Overflow!</p>
<p>@rohatgisanat might be right but without seeing your current configs it's impossible to verify that. Please check if that was the case.</p>
<p>There are also two other things you should look for:</p>
<ol>
<li>If there was any previous installations of other prometheus-relevant manifest files than delete the following:</li>
</ol>
<ul>
<li><code>crd alertmanagerconfigs.monitoring.coreos.com</code></li>
<li><code>alertmanagers.monitoring.coreos.com</code></li>
<li><code>crd podmonitors.monitoring.coreos.com</code></li>
<li><code>crd probes.monitoring.coreos.com</code></li>
<li><code>crd prometheuses.monitoring.coreos.com</code></li>
<li><code>crd prometheusrules.monitoring.coreos.com</code></li>
<li><code>crd servicemonitors.monitoring.coreos.com</code></li>
<li><code>crd thanosrulers.monitoring.coreos.com</code></li>
</ul>
<p>Also, check if there are any other Prometheus related config files with:</p>
<pre><code>kubectl get configmap --all-namespaces
</code></pre>
<p>and also delete them.</p>
<p>Notice that deleting the CRDs will result in deleting any servicemonitors and so on, which have previously been created by other charts.</p>
<p>After that you can try to install again from scratch.</p>
<ol start="2">
<li>If installing fresh, run:</li>
</ol>
<hr />
<pre><code>kubectl apply -f  https://raw.githubusercontent.com/prometheus-operator/prometheus-operator/v0.45.0/example/prometheus-operator-crd/monitoring.coreos.com_alertmanagers.yaml
</code></pre>
<hr />
<p>as CRD changed with the newer version and you need to use the updated ones.</p>
<p><a href="https://github.com/prometheus-community/helm-charts/issues/557" rel="nofollow noreferrer">Source</a>.</p>
