Installed DX 7.0.12 community edition on Red Hat Linux v7.9, with MariaDB. Try to install app Internal Service Request from marketplace but it fails. The same import attempt works on windows server. Catalina.out log file has the following error:

27-Jan-2021 13:42:29.043 INFO [main] org.apache.catalina.startup.Catalina.start Server startup in 29516 ms
INFO 27 Jan 2021 13:43:46 org.joget.apps.workflow.security.WorkflowAuthenticationProvider - Authentication for user admin (198.118.112.36) : true
INFO 27 Jan 2021 13:44:45 org.joget.apps.app.service.AppServiceImpl - Importing app isr ...
INFO 27 Jan 2021 13:44:47 org.joget.apps.app.service.AppDevUtil - Commit to Git repo by admin: Initial commit for isr_2
INFO 27 Jan 2021 13:44:49 org.joget.apps.app.service.AppServiceImpl - Imported form definitions : 8
INFO 27 Jan 2021 13:44:49 org.joget.apps.app.service.AppServiceImpl - Imported datalist definitions : 8
INFO 27 Jan 2021 13:44:49 org.joget.apps.app.service.AppServiceImpl - Imported userview definitions : 1
INFO 27 Jan 2021 13:44:50 org.joget.apps.app.service.AppServiceImpl - Imported messages : 90
INFO 27 Jan 2021 13:44:50 org.joget.apps.app.service.AppServiceImpl - Imported app resources : 4
org.enhydra.shark.api.client.wfservice.PackageInvalid: Error in package
at org.enhydra.shark.PackageAdmin.openPackage(PackageAdmin.java:818)
at org.enhydra.shark.PackageAdmin.uploadPackage(PackageAdmin.java:238)
at org.joget.workflow.model.service.WorkflowManagerImpl.processUpload(WorkflowManagerImpl.java:946)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)

...

ERROR 27 Jan 2021 13:44:59 Shark - PackageAdmin -> Package byte[] representation failed to open
ERROR 27 Jan 2021 13:44:59 org.joget.workflow.model.service.WorkflowManagerImpl - Type=ERROR, Sub-Type=SCHEMA, Location=Package 'isr': __: [Warning] at line number 2: schema_reference.4: Failed to read schema document 'http://wfmc.org/standards/docs/TC-1025_schema_10_xpdl.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>._____Type=ERROR, Sub-Type=SCHEMA, Location=Package 'isr': __: [Error] at line number 2: cvc-elt.1.a: Cannot find the declaration of element 'Package'._____Type=ERROR, Sub-Type=SCHEMA, Location=Package 'isr': __: [Warning] at line number 3: schema_reference.4: Failed to read schema document 'http://wfmc.org/standards/docs/TC-1025_schema_10_xpdl.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>._____Type=ERROR, Sub-Type=SCHEMA, Location=Package 'isr': __: [Warning] at line number 4: schema_reference.4: Failed to read schema document 'http://wfmc.org/standards/docs/TC-1025_schema_10_xpdl.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>._____Type=ERROR, Sub-Type=SCHEMA, Location=Package 'isr': __: [Warning] at line number 5: schema_reference.4: Failed to read

...

number 215: schema_reference.4: Failed to read schema document 'http://wfmc.org/standards/docs/TC-1025_schema_10_xpdl.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>._____Type=ERROR, Sub-Type=SCHEMA, Location=Package 'isr': __: [Warning] at line number 216: schema_reference.4: Failed to read schema document 'http://wfmc.org/standards/docs/TC-1025_schema_10_xpdl.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>._____Type=WARNING, Sub-Type=LOGIC, Location=Package 'isr', WorkflowProcess 'isr', Activity 'route1' -> Performer: __Activity can't have performer____Type=WARNING, Sub-Type=LOGIC, Location=Package 'isr', WorkflowProcess 'isr', Activity 'route2' -> Performer: __Activity can't have performer____
org.enhydra.shark.api.client.wfservice.PackageInvalid: Error in package
at org.enhydra.shark.PackageAdmin.openPackage(PackageAdmin.java:818)
at org.enhydra.shark.PackageAdmin.uploadPackage(PackageAdmin.java:238)
at org.joget.workflow.model.service.WorkflowManagerImpl.processUpload(WorkflowManagerImpl.java:946)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)