licensere reTry (#5763)

# Description of Changes

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- What was changed
- Why the change was made
- Any challenges encountered

Closes #(issue_number)
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## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### Translations (if applicable)

- [ ] I ran
[`scripts/counter_translation.py`](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/docs/counter_translation.md)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

app/proprietary/src/main/java/stirling/software/proprietary/security/configuration/ee/KeygenLicenseVerifier.java

@@ -480,12 +480,17 @@ public class KeygenLicenseVerifier {
     }
 
     private boolean verifyStandardLicense(String licenseKey, LicenseContext context) {
+        int maxRetries = 5;
+        Exception lastException = null;
+
+        for (int attempt = 1; attempt <= maxRetries; attempt++) {
             try {
-            log.info("Checking standard license key");
+                log.info("Checking standard license key (attempt {}/{})", attempt, maxRetries);
                 String machineFingerprint = generateMachineFingerprint();
 
                 // First, try to validate the license
-            JsonNode validationResponse = validateLicense(licenseKey, machineFingerprint, context);
+                JsonNode validationResponse =
+                        validateLicense(licenseKey, machineFingerprint, context);
                 if (validationResponse != null) {
                     boolean isValid = validationResponse.path("meta").path("valid").asBoolean();
                     String licenseId = validationResponse.path("data").path("id").asText();
@@ -499,7 +504,8 @@ public class KeygenLicenseVerifier {
                                     "License not activated for this machine. Attempting to"
                                             + " activate...");
                             boolean activated =
-                                activateMachine(licenseKey, licenseId, machineFingerprint, context);
+                                    activateMachine(
+                                            licenseKey, licenseId, machineFingerprint, context);
                             if (activated) {
                                 // Revalidate after activation
                                 validationResponse =
@@ -518,10 +524,30 @@ public class KeygenLicenseVerifier {
 
                 return false;
             } catch (Exception e) {
-            log.error("Error verifying standard license: {}", e.getMessage());
+                lastException = e;
-            return false;
+                log.error(
+                        "Error verifying standard license (attempt {}/{}): {}",
+                        attempt,
+                        maxRetries,
+                        e.getMessage());
+                if (attempt < maxRetries) {
+                    try {
+                        Thread.sleep(3000L * attempt);
+                    } catch (InterruptedException ie) {
+                        Thread.currentThread().interrupt();
+                        break;
                     }
                 }
+            }
+        }
+
+        throw new RuntimeException(
+                "License verification failed after "
+                        + maxRetries
+                        + " attempts: "
+                        + (lastException != null ? lastException.getMessage() : "unknown error"),
+                lastException);
+    }
 
     private JsonNode validateLicense(
             String licenseKey, String machineFingerprint, LicenseContext context) throws Exception {

app/proprietary/src/main/java/stirling/software/proprietary/security/configuration/ee/LicenseKeyChecker.java

@@ -55,7 +55,14 @@ public class LicenseKeyChecker {
 
     @Scheduled(initialDelay = 604800000, fixedRate = 604800000) // 7 days in milliseconds
     public void checkLicensePeriodically() {
+        try {
             evaluateLicense();
+        } catch (RuntimeException e) {
+            log.error(
+                    "Periodic license check failed after all retries: {}. Keeping existing license"
+                            + " status.",
+                    e.getMessage());
+        }
         synchronizeLicenseSettings();
     }