diff --git a/.eslintignore b/.eslintignore
index 94f2f34897..1578d94346 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -513,6 +513,7 @@ packages/lib/markdownUtils.js
 packages/lib/markdownUtils.test.js
 packages/lib/markdownUtils2.test.js
 packages/lib/markupLanguageUtils.js
+packages/lib/migrations/42.js
 packages/lib/models/Alarm.js
 packages/lib/models/BaseItem.js
 packages/lib/models/Folder.js
@@ -759,6 +760,8 @@ packages/lib/themes/type.js
 packages/lib/time.js
 packages/lib/utils/credentialFiles.js
 packages/lib/utils/joplinCloud.js
+packages/lib/utils/webDAVUtils.js
+packages/lib/utils/webDAVUtils.test.js
 packages/lib/uuid.js
 packages/lib/versionInfo.js
 packages/lib/versionInfo.test.js
diff --git a/.gitignore b/.gitignore
index 158260c481..1bd166dd5f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -501,6 +501,7 @@ packages/lib/markdownUtils.js
 packages/lib/markdownUtils.test.js
 packages/lib/markdownUtils2.test.js
 packages/lib/markupLanguageUtils.js
+packages/lib/migrations/42.js
 packages/lib/models/Alarm.js
 packages/lib/models/BaseItem.js
 packages/lib/models/Folder.js
@@ -747,6 +748,8 @@ packages/lib/themes/type.js
 packages/lib/time.js
 packages/lib/utils/credentialFiles.js
 packages/lib/utils/joplinCloud.js
+packages/lib/utils/webDAVUtils.js
+packages/lib/utils/webDAVUtils.test.js
 packages/lib/uuid.js
 packages/lib/versionInfo.js
 packages/lib/versionInfo.test.js
diff --git a/packages/lib/JoplinDatabase.ts b/packages/lib/JoplinDatabase.ts
index 3b6d5c65aa..40275cbc6d 100644
--- a/packages/lib/JoplinDatabase.ts
+++ b/packages/lib/JoplinDatabase.ts
@@ -354,7 +354,7 @@ export default class JoplinDatabase extends Database {
 		// must be set in the synchronizer too.
 
 		// Note: v16 and v17 don't do anything. They were used to debug an issue.
-		const existingDatabaseVersions = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41];
+		const existingDatabaseVersions = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42];
 
 		let currentVersionIndex = existingDatabaseVersions.indexOf(fromVersion);
 
@@ -913,6 +913,10 @@ export default class JoplinDatabase extends Database {
 				queries.push('ALTER TABLE `folders` ADD COLUMN icon TEXT NOT NULL DEFAULT ""');
 			}
 
+			if (targetVersion === 42) {
+				queries.push(this.addMigrationFile(42));
+			}
+
 			const updateVersionQuery = { sql: 'UPDATE version SET version = ?', params: [targetVersion] };
 
 			queries.push(updateVersionQuery);
diff --git a/packages/lib/SyncTargetWebDAV.js b/packages/lib/SyncTargetWebDAV.js
index 85d4c378ae..ac16391686 100644
--- a/packages/lib/SyncTargetWebDAV.js
+++ b/packages/lib/SyncTargetWebDAV.js
@@ -5,6 +5,7 @@ const { FileApi } = require('./file-api.js');
 const Synchronizer = require('./Synchronizer').default;
 const WebDavApi = require('./WebDavApi');
 const { FileApiDriverWebDav } = require('./file-api-driver-webdav');
+const checkProviderIsSupported = require('./utils/webDAVUtils').default;
 
 class SyncTargetWebDAV extends BaseSyncTarget {
 	static id() {
@@ -56,6 +57,7 @@ class SyncTargetWebDAV extends BaseSyncTarget {
 		};
 
 		try {
+			checkProviderIsSupported(options.path());
 			const result = await fileApi.stat('');
 			if (!result) throw new Error(`WebDAV directory not found: ${options.path()}`);
 			output.ok = true;
diff --git a/packages/lib/file-api-driver-webdav.js b/packages/lib/file-api-driver-webdav.js
index fd12226d61..06b08d279f 100644
--- a/packages/lib/file-api-driver-webdav.js
+++ b/packages/lib/file-api-driver-webdav.js
@@ -1,6 +1,8 @@
 const { basicDelta } = require('./file-api');
 const { rtrimSlashes, ltrimSlashes } = require('./path-utils');
 const JoplinError = require('./JoplinError').default;
+const Setting = require('./models/Setting').default;
+const checkProviderIsSupported = require('./utils/webDAVUtils').default;
 
 class FileApiDriverWebDav {
 	constructor(api) {
@@ -224,6 +226,10 @@ class FileApiDriverWebDav {
 		await this.delete('');
 		await this.mkdir('');
 	}
+
+	initialize() {
+		checkProviderIsSupported(Setting.value('sync.6.path'));
+	}
 }
 
 module.exports = { FileApiDriverWebDav };
diff --git a/packages/lib/migrations/42.ts b/packages/lib/migrations/42.ts
new file mode 100644
index 0000000000..64c2795f4b
--- /dev/null
+++ b/packages/lib/migrations/42.ts
@@ -0,0 +1,21 @@
+import Setting from '../models/Setting';
+import checkProviderIsSupported from '../utils/webDAVUtils';
+
+interface Script {
+  exec: ()=> Promise<void>;
+}
+
+const script: Script = <Script>{};
+
+script.exec = async () => {
+	try {
+		checkProviderIsSupported(Setting.value('sync.6.path'));
+		Setting.setValue('sync.allowUnsupportedProviders', 0);
+	} catch (error) {
+		Setting.setValue('sync.allowUnsupportedProviders', 1);
+	}
+};
+
+export default script;
+
+
diff --git a/packages/lib/models/Migration.ts b/packages/lib/models/Migration.ts
index 4c42171fe5..b53d1f4c84 100644
--- a/packages/lib/models/Migration.ts
+++ b/packages/lib/models/Migration.ts
@@ -1,10 +1,12 @@
 import BaseModel from '../BaseModel';
+import migration42 from '../migrations/42';
 
 const migrationScripts: Record<number, any> = {
 	20: require('../migrations/20.js'),
 	27: require('../migrations/27.js'),
 	33: require('../migrations/33.js'),
 	35: require('../migrations/35.js'),
+	42: migration42,
 };
 
 export default class Migration extends BaseModel {
diff --git a/packages/lib/models/Setting.ts b/packages/lib/models/Setting.ts
index 2d7d0f746c..9a1df3741b 100644
--- a/packages/lib/models/Setting.ts
+++ b/packages/lib/models/Setting.ts
@@ -1671,6 +1671,12 @@ class Setting extends BaseModel {
 			// 	storage: SettingStorage.File,
 			// },
 
+			'sync.allowUnsupportedProviders': {
+				value: -1,
+				type: SettingItemType.Int,
+				public: false,
+			},
+
 		};
 
 		this.metadata_ = Object.assign(this.metadata_, this.customMetadata_);
diff --git a/packages/lib/utils/webDAVUtils.test.ts b/packages/lib/utils/webDAVUtils.test.ts
new file mode 100644
index 0000000000..f0d0a425df
--- /dev/null
+++ b/packages/lib/utils/webDAVUtils.test.ts
@@ -0,0 +1,43 @@
+import checkProviderIsSupported from './webDAVUtils';
+import Setting from '../models/Setting';
+
+describe('checkProviderIsSupported', () => {
+	describe('when no unsupported provider is already configured', () => {
+		beforeAll(() => {
+			Setting.setValue('sync.allowUnsupportedProviders', 0);
+		});
+
+		it('should not throw when no provider path is provided ', () => {
+			expect(() => checkProviderIsSupported('')).not.toThrow();
+		});
+
+		it('should not throw when a valid provider path is provided', () => {
+			expect(() => checkProviderIsSupported('https://good-webdav-provider.com')).not.toThrow();
+		});
+
+		it('should not throw when a valid provider path with a name that contains an unsupported provider is provided', () => {
+			expect(() => checkProviderIsSupported('https://hopcloudabc.com')).not.toThrow();
+		});
+
+		it('should throw an error with the name of the provider when an unsupported provider path is provided', () => {
+			expect(() => checkProviderIsSupported('https://pcloud.com')).toThrowError('The WebDAV implementation of pcloud is incompatible with Joplin, and as such is no longer supported. Please use a different sync method.');
+
+			expect(() => checkProviderIsSupported('https://api.pcloud.com')).toThrowError('The WebDAV implementation of pcloud is incompatible with Joplin, and as such is no longer supported. Please use a different sync method.');
+
+			expect(() => checkProviderIsSupported('https://api-pcloud-test.com')).toThrowError('The WebDAV implementation of pcloud is incompatible with Joplin, and as such is no longer supported. Please use a different sync method.');
+		});
+		expect(() => checkProviderIsSupported('?param=pcloud')).toThrowError('The WebDAV implementation of pcloud is incompatible with Joplin, and as such is no longer supported. Please use a different sync method.');
+	});
+
+	describe('when an unsupported provider is already configured', () => {
+		beforeAll(() => {
+			Setting.setValue('sync.allowUnsupportedProviders', 1);
+		});
+
+		it('should not throw when an unsupported provider is already configured', () => {
+			expect(() => checkProviderIsSupported('pcloud')).not.toThrow();
+		});
+
+	});
+});
+
diff --git a/packages/lib/utils/webDAVUtils.ts b/packages/lib/utils/webDAVUtils.ts
new file mode 100644
index 0000000000..e0e399d1ac
--- /dev/null
+++ b/packages/lib/utils/webDAVUtils.ts
@@ -0,0 +1,21 @@
+import { _ } from '../locale';
+import Setting from '../models/Setting';
+
+export const checkProviderIsSupported = (path: string): void => {
+	if (Setting.value('sync.allowUnsupportedProviders') === 1) return;
+
+	const unsupportedProviders = ['pcloud', 'jianguoyun'];
+	for (const p of unsupportedProviders) {
+		// For a provider named abc, this regex will match the provider's name if enclosed by either '/', '.', '-', '=' or end of string.
+		// E.g: https://abc.com, https://api.abc.com, https://api-abc-test.com, https://api/test?param=abc
+		//
+		// It will not match a provider which name happens to contain an unsupported provider (i.e a substring).
+		// E.g: https://fooabc.com
+		const pattern = `(?<=[-/.=])${p}(?=[-/.=]|$)`;
+		if (path.search(new RegExp(pattern)) !== -1) {
+			throw new Error(_('The WebDAV implementation of %s is incompatible with Joplin, and as such is no longer supported. Please use a different sync method.', p));
+		}
+	}
+};
+
+export default checkProviderIsSupported;