Merge branch 'fix-versioning-button-7.6'

Author: alexandrevryghem

src/app/core/data/version-history-data.service.ts

@@ -190,7 +190,7 @@ export class VersionHistoryDataService extends IdentifiableDataService<VersionHi
     return this.versionDataService.findByHref(versionHref, false, true, followLink('versionhistory')).pipe(
       getFirstCompletedRemoteData(),
       switchMap((versionRD: RemoteData<Version>) => {
-        if (versionRD.hasSucceeded && !versionRD.hasNoContent) {
+        if (versionRD.hasSucceeded && !versionRD.hasNoContent && hasValue(versionRD.payload)) {
           return versionRD.payload.versionhistory.pipe(
             getFirstCompletedRemoteData(),
             map((versionHistoryRD: RemoteData<VersionHistory>) => {