diff --git a/__tests__/versionutil.test.ts b/__tests__/versionutil.test.ts
index a238688..69681da 100644
--- a/__tests__/versionutil.test.ts
+++ b/__tests__/versionutil.test.ts
@@ -13,6 +13,8 @@ describe('version tests', () => {
   );
 
   each([
+    ['3.x', '3.x'],
+    ['3.*', '3.*'],
     ['3.1.x', '3.1'],
     ['1.1.*', '1.1'],
     ['2.0', '2.0']
@@ -42,7 +44,6 @@ describe('version tests', () => {
     '.2.3',
     '.2.x',
     '1',
-    '2.x',
     '*.*.1',
     '*.1',
     '*.',
diff --git a/dist/index.js b/dist/index.js
index 6ef97ad..798e67e 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -4840,7 +4840,9 @@ const github = __importStar(__webpack_require__(469));
 const xmlbuilder = __importStar(__webpack_require__(312));
 const xmlParser = __importStar(__webpack_require__(989));
 function configAuthentication(feedUrl, existingFileLocation = '', processRoot = process.cwd()) {
-    const existingNuGetConfig = path.resolve(processRoot, existingFileLocation == '' ? 'nuget.config' : existingFileLocation);
+    const existingNuGetConfig = path.resolve(processRoot, existingFileLocation === ''
+        ? getExistingNugetConfig(processRoot)
+        : existingFileLocation);
     const tempNuGetConfig = path.resolve(processRoot, '../', 'nuget.config');
     writeFeedToFile(feedUrl, existingNuGetConfig, tempNuGetConfig);
 }
@@ -4848,6 +4850,16 @@ exports.configAuthentication = configAuthentication;
 function isValidKey(key) {
     return /^[\w\-\.]+$/i.test(key);
 }
+function getExistingNugetConfig(processRoot) {
+    const defaultConfigName = 'nuget.config';
+    const configFileNames = fs
+        .readdirSync(processRoot)
+        .filter(filename => filename.toLowerCase() === defaultConfigName);
+    if (configFileNames.length) {
+        return configFileNames[0];
+    }
+    return defaultConfigName;
+}
 function writeFeedToFile(feedUrl, existingFileLocation, tempFileLocation) {
     console.log(`dotnet-auth: Finding any source references in ${existingFileLocation}, writing a new temporary configuration file with credentials to ${tempFileLocation}`);
     let xml;
@@ -16872,14 +16884,16 @@ class DotNetVersionInfo {
             return;
         }
         //Note: No support for previews when using generic
-        let parts = version.split('.');
+        const parts = version.split('.');
         if (parts.length < 2 || parts.length > 3)
             this.throwInvalidVersionFormat();
         if (parts.length == 3 && parts[2] !== 'x' && parts[2] !== '*') {
             this.throwInvalidVersionFormat();
         }
-        let major = this.getVersionNumberOrThrow(parts[0]);
-        let minor = this.getVersionNumberOrThrow(parts[1]);
+        const major = this.getVersionNumberOrThrow(parts[0]);
+        const minor = ['x', '*'].includes(parts[1])
+            ? parts[1]
+            : this.getVersionNumberOrThrow(parts[1]);
         this.fullversion = major + '.' + minor;
     }
     getVersionNumberOrThrow(input) {
@@ -16897,7 +16911,7 @@ class DotNetVersionInfo {
         }
     }
     throwInvalidVersionFormat() {
-        throw 'Invalid version format! Supported: 1.2.3, 1.2, 1.2.x, 1.2.*';
+        throw new Error('Invalid version format! Supported: 1.2.3, 1.2, 1.2.x, 1.2.*');
     }
     /**
      * If true exacatly one version should be resolved
@@ -17000,7 +17014,7 @@ class DotnetCoreInstaller {
             }
             console.log(process.env['PATH']);
             if (resultCode != 0) {
-                throw `Failed to install dotnet ${resultCode}. ${output}`;
+                throw new Error(`Failed to install dotnet ${resultCode}. ${output}`);
             }
         });
     }
@@ -17028,7 +17042,7 @@ class DotnetCoreInstaller {
             // Sort for latest version
             releasesInfo = releasesInfo.sort((a, b) => semver.rcompare(a['sdk']['version'], b['sdk']['version']));
             if (releasesInfo.length == 0) {
-                throw `Could not find dotnet core version. Please ensure that specified version ${versionInfo.inputVersion} is valid.`;
+                throw new Error(`Could not find dotnet core version. Please ensure that specified version ${versionInfo.inputVersion} is valid.`);
             }
             let release = releasesInfo[0];
             return release['sdk']['version'];
@@ -17049,7 +17063,7 @@ class DotnetCoreInstaller {
                 return versionParts[0] == sdkParts[0];
             });
             if (releasesInfo.length === 0) {
-                throw `Could not find info for version ${versionParts.join('.')} at ${DotNetCoreIndexUrl}`;
+                throw new Error(`Could not find info for version ${versionParts.join('.')} at ${DotNetCoreIndexUrl}`);
             }
             return releasesInfo[0]['releases.json'];
         });
diff --git a/package-lock.json b/package-lock.json
index da3c738..e5a85ed 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -5342,9 +5342,9 @@
       "dev": true
     },
     "y18n": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.0.tgz",
-      "integrity": "sha512-r9S/ZyXu/Xu9q1tYlpsLIsa3EeLXXk0VwlxqTcFRfg9EhMW+17kbt9G0NrgCmhGb5vT2hyhJZLfDGx+7+5Uj/w==",
+      "version": "4.0.1",
+      "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.1.tgz",
+      "integrity": "sha512-wNcy4NvjMYL8gogWWYAO7ZFWFfHcbdbE57tZO8e4cbpj8tfUcwrwqSl3ad8HxpYWCdXcJUCeKKZS62Av1affwQ==",
       "dev": true
     },
     "yaml": {
diff --git a/src/authutil.ts b/src/authutil.ts
index faf98ab..9599979 100644
--- a/src/authutil.ts
+++ b/src/authutil.ts
@@ -13,7 +13,9 @@ export function configAuthentication(
 ) {
   const existingNuGetConfig: string = path.resolve(
     processRoot,
-    existingFileLocation == '' ? 'nuget.config' : existingFileLocation
+    existingFileLocation === ''
+      ? getExistingNugetConfig(processRoot)
+      : existingFileLocation
   );
 
   const tempNuGetConfig: string = path.resolve(
@@ -29,6 +31,17 @@ function isValidKey(key: string): boolean {
   return /^[\w\-\.]+$/i.test(key);
 }
 
+function getExistingNugetConfig(processRoot: string) {
+  const defaultConfigName = 'nuget.config';
+  const configFileNames = fs
+    .readdirSync(processRoot)
+    .filter(filename => filename.toLowerCase() === defaultConfigName);
+  if (configFileNames.length) {
+    return configFileNames[0];
+  }
+  return defaultConfigName;
+}
+
 function writeFeedToFile(
   feedUrl: string,
   existingFileLocation: string,
diff --git a/src/installer.ts b/src/installer.ts
index f0b48a2..d0bc4f4 100644
--- a/src/installer.ts
+++ b/src/installer.ts
@@ -30,7 +30,7 @@ export class DotNetVersionInfo {
     }
 
     //Note: No support for previews when using generic
-    let parts: string[] = version.split('.');
+    const parts: string[] = version.split('.');
 
     if (parts.length < 2 || parts.length > 3) this.throwInvalidVersionFormat();
 
@@ -38,8 +38,10 @@ export class DotNetVersionInfo {
       this.throwInvalidVersionFormat();
     }
 
-    let major = this.getVersionNumberOrThrow(parts[0]);
-    let minor = this.getVersionNumberOrThrow(parts[1]);
+    const major = this.getVersionNumberOrThrow(parts[0]);
+    const minor = ['x', '*'].includes(parts[1])
+      ? parts[1]
+      : this.getVersionNumberOrThrow(parts[1]);
 
     this.fullversion = major + '.' + minor;
   }
@@ -60,7 +62,9 @@ export class DotNetVersionInfo {
   }
 
   private throwInvalidVersionFormat() {
-    throw 'Invalid version format! Supported: 1.2.3, 1.2, 1.2.x, 1.2.*';
+    throw new Error(
+      'Invalid version format! Supported: 1.2.3, 1.2, 1.2.x, 1.2.*'
+    );
   }
 
   /**
@@ -187,7 +191,7 @@ export class DotnetCoreInstaller {
     console.log(process.env['PATH']);
 
     if (resultCode != 0) {
-      throw `Failed to install dotnet ${resultCode}. ${output}`;
+      throw new Error(`Failed to install dotnet ${resultCode}. ${output}`);
     }
   }
 
@@ -236,7 +240,9 @@ export class DotnetCoreInstaller {
     );
 
     if (releasesInfo.length == 0) {
-      throw `Could not find dotnet core version. Please ensure that specified version ${versionInfo.inputVersion} is valid.`;
+      throw new Error(
+        `Could not find dotnet core version. Please ensure that specified version ${versionInfo.inputVersion} is valid.`
+      );
     }
 
     let release = releasesInfo[0];
@@ -264,9 +270,11 @@ export class DotnetCoreInstaller {
     });
 
     if (releasesInfo.length === 0) {
-      throw `Could not find info for version ${versionParts.join(
-        '.'
-      )} at ${DotNetCoreIndexUrl}`;
+      throw new Error(
+        `Could not find info for version ${versionParts.join(
+          '.'
+        )} at ${DotNetCoreIndexUrl}`
+      );
     }
 
     return releasesInfo[0]['releases.json'];